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Zhu S, Tomaiuolo M, Diamond SL. Minimum wound size for clotting: flowing blood coagulates on a single collagen fiber presenting tissue factor and von Willebrand factor. Integr Biol (Camb) 2016; 8:813-20. [PMID: 27339024 PMCID: PMC4980166 DOI: 10.1039/c6ib00077k] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
It is unknown if a lower size limit exists for human blood coagulation under flow over physiological vessel wall triggers as small as a single collagen fiber. Prior determinations of the smallest sized surface stimuli necessary for clotting of human blood, defined as the patch size threshold, have not deployed whole blood, hemodynamic flow, and platelet adhesive stimuli. For whole blood perfused in microfluidic devices, we report that steady venous flow (wall shear rate, 100 s(-1)) was sufficient to drive platelet deposition on 20 micron long zones of collagen fibers or on a single fiber. With tissue factor (TF)-coated collagen, flowing blood generated robust platelet deposits, platelet-localized thrombin, and fibrin on a single collagen fiber, thus demonstrating the absence of a physiological patch size threshold under venous flow. In contrast, at arterial wall shear rate (1000 s(-1)) with TF present, essentially no platelet or fibrin deposition occurred on 20 micron collagen zones or on a single collagen fiber, demonstrating a patch threshold, which was overcome by pre-coating the collagen with von Willebrand factor (vWF). For venous flows, human blood can clot on one of the smallest biological units of a single collagen fiber presenting TF. For arterial flows, vWF together with TF allows human blood to generate thrombin and fibrin on a patch stimulus as limited as a single collagen fiber. vWF-dependent platelet adhesion represents a particle-based sensing mechanism of micron-scale stimuli that then allows amplification of the molecular components of TF-driven thrombin and fibrin production under arterial flow.
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Affiliation(s)
- Shu Zhu
- Institute for Medicine and Engineering, University of Pennsylvania, 1024 Vagelos Research Laboratories, Philadelphia, PA 19104, USA.
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French SL, Arthur JF, Lee H, Nesbitt WS, Andrews RK, Gardiner EE, Hamilton JR. Inhibition of protease-activated receptor 4 impairs platelet procoagulant activity during thrombus formation in human blood. J Thromb Haemost 2016; 14:1642-54. [PMID: 26878340 DOI: 10.1111/jth.13293] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 01/26/2016] [Indexed: 01/11/2023]
Abstract
UNLABELLED Essentials The platelet thrombin receptor, PAR4, is an emerging anti-thrombotic drug target. We examined the anti-platelet & anti-thrombotic effects of PAR4 inhibition in human blood. PAR4 inhibition impaired platelet procoagulant activity in isolated cells and during thrombosis. Our study shows PAR4 is required for platelet procoagulant function & thrombosis in human blood. SUMMARY Background Thrombin-induced platelet activation is important for arterial thrombosis. Thrombin activates human platelets predominantly via protease-activated receptor (PAR)1 and PAR4. PAR1 has higher affinity for thrombin, and the first PAR1 antagonist, vorapaxar, was recently approved for use as an antiplatelet agent. However, vorapaxar is contraindicated in a significant number of patients, owing to adverse bleeding events. Consequently, there is renewed interest in the role of platelet PAR4 in the setting of thrombus formation. Objectives To determine the specific antiplatelet effects of inhibiting PAR4 function during thrombus formation in human whole blood. Methods and Results We developed a rabbit polyclonal antibody against the thrombin cleavage site of PAR4, and showed it to be a highly specific inhibitor of PAR4-mediated platelet function. This function-blocking anti-PAR4 antibody was used to probe for PAR4-dependent platelet functions in human isolated platelets in the absence and presence of concomitant PAR1 inhibition. The anti-PAR4 antibody alone was sufficient to abolish the sustained elevation of cytosolic calcium level and consequent phosphatidylserine exposure induced by thrombin, but did not significantly inhibit integrin αII b β3 activation, α-granule secretion, or aggregation. In accord with these in vitro experiments on isolated platelets, selective inhibition of PAR4, but not of PAR1, impaired thrombin activity (fluorescence resonance energy transfer-based thrombin sensor) and fibrin formation (anti-fibrin antibody) in an ex vivo whole blood flow thrombosis assay. Conclusions These findings demonstrate that PAR4 is required for platelet procoagulant function during thrombus formation in human blood, and suggest PAR4 inhibition as a potential target for the prevention of arterial thrombosis.
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Affiliation(s)
- S L French
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - J F Arthur
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - H Lee
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - W S Nesbitt
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
- Microplatforms Research Group, School of Engineering, RMIT University, Melbourne, Australia
| | - R K Andrews
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - E E Gardiner
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - J R Hamilton
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
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Colucci M, Incampo F, Cannavò A, Menegatti M, Siboni SM, Zaccaria F, Semeraro N, Peyvandi F. Reduced fibrinolytic resistance in patients with factor XI deficiency. Evidence of a thrombin-independent impairment of the thrombin-activatable fibrinolysis inhibitor pathway. J Thromb Haemost 2016; 14:1603-14. [PMID: 27094709 DOI: 10.1111/jth.13342] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Indexed: 11/30/2022]
Abstract
UNLABELLED Essentials Plasma of factor XI-deficient patients (FXI-dp) displays enhanced fibrinolysis. We investigated the role of thrombin activatable fibrinolysis inhibitor (TAFI) in 18 FXI-dp. FXI-dp generated less activated TAFI (TAFIa) on clotting challenge and were resistant to TAFIa. TAFI activation and TAFIa resistance correlated with bleeding score and bleeding phenotype. SUMMARY Background Factor XI (FXI) deficiency, a rare disorder with unpredictable bleeding, has been associated with reduced fibrinolytic resistance as a result of abnormal fibrin density. Objective We investigated the involvement of thrombin-activatable fibrinolysis inhibitor (TAFI) in the increased lysability of FXI-deficient (FXI-def) clots and the role of thrombin. Patients/Methods Eighteen patients with FXI deficiency (1-58%) and 17 matched controls were investigated for fibrinolytic resistance to t-PA, thrombin generation, TAFI activation and response to TAFIa. Results When clotting was induced by 0.5 pm tissue factor (TF), FXI-def plasmas displayed less thrombin and TAFIa generation and shorter lysis time than controls. A 100-fold higher TF concentration (to bypass FXI) abolished the difference in thrombin generation but not in lysis time between patients and controls. Normalization of FXI levels by a FXI concentrate increased thrombin generation but had no effect on the lysis time of FXI-def plasma. Moreover, when clots were induced by purified thrombin and high concentrations of FXa inhibitor, FXI-def plasma still generated less TAFIa and displayed a shorter lysis time than controls. Finally, upon TAFIa addition, the lysis time of FXI-def plasma was prolonged significantly less than that of control plasma, suggesting a TAFIa resistance. TAFIa generation and TAFIa resistance were correlated with the bleeding score, displaying a considerable capacity to discriminate between patients with and without bleeding. Conclusions TAFI pathway impairment, largely caused by a hitherto unknown TAFIa resistance, appears to be one main cause of decreased fibrinolytic resistance in FXI deficiency and might be clinically useful for assessing the bleeding risk of FXI-def patients.
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Affiliation(s)
- M Colucci
- Department of Biomedical Sciences and Human Oncology, Section of General and Experimental Pathology, Aldo Moro University, Bari, Italy
| | - F Incampo
- Department of Biomedical Sciences and Human Oncology, Section of General and Experimental Pathology, Aldo Moro University, Bari, Italy
| | - A Cannavò
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
| | - M Menegatti
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Centre, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - S M Siboni
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
| | - F Zaccaria
- Department of Biomedical Sciences and Human Oncology, Section of General and Experimental Pathology, Aldo Moro University, Bari, Italy
| | - N Semeraro
- Department of Biomedical Sciences and Human Oncology, Section of General and Experimental Pathology, Aldo Moro University, Bari, Italy
| | - F Peyvandi
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Centre, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
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Rathnakumar K, Savant S, Giri H, Ghosh A, Fisslthaler B, Fleming I, Ram U, Bera AK, Augustin HG, Dixit M. Angiopoietin-2 mediates thrombin-induced monocyte adhesion and endothelial permeability. J Thromb Haemost 2016; 14:1655-67. [PMID: 27241812 DOI: 10.1111/jth.13376] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 05/04/2016] [Indexed: 02/03/2023]
Abstract
UNLABELLED Essentials Mechanism of thrombin-induced inflammation is not fully understood. Thrombin induced monocyte adhesion and barrier loss require Angiopoietin-2 (Ang-2). Ang-2 mediates vessel leakage and monocyte adhesion through SHP-2/p38MAPK pathway. Calcium dependent SHP2/p38MAPK activation regulates Ang-2 expression through a feedback loop. SUMMARY Background Thrombin imparts an inflammatory phenotype to the endothelium by promoting increased monocyte adhesion and vascular permeability. However, the molecular players that govern these events are incompletely understood. Objective The aim of this study was to determine whether Angiopoietin-2 (Ang-2) has a role, if any, in regulating inflammatory signals initiated by thrombin. Methods Assessment of vascular leakage by Miles assay was performed by intra-dermal injection on the foot paw. Surface levels of intercellular adhesion molecule-1 (ICAM-1) were determined by flow cytometry. Overexpression, knockdown and phosphorylation of proteins were determined by Western blotting. Results In time-course experiments, thrombin-stimulated Ang-2 up-regulation, peaked prior to the expression of adhesion molecule ICAM-1 in human umbilical vein-derived endothelial cells (HUVECs). Knockdown of Ang-2 blocked both thrombin-induced monocyte adhesion and ICAM-1 expression. In addition, Ang-2(-/-) mice displayed defective vascular leakage when treated with thrombin. Introducing Ang-2 protein in Ang-2(-/-) mice failed to recover a wild-type phenotype. Mechanistically, Ang-2 appears to regulate the thrombin-activated calcium spike that is required for tyrosine phosphatase SHP2 and p38 MAPK activation. Further, down-regulation of SHP2 attenuated both thrombin-induced Ang-2 expression and monocyte adhesion. Down-regulation of the adaptor protein Gab1, a co-activator of SHP2, as well as overexpression of the Gab1 mutant incapable of interacting with SHP2 (YFGab1), inhibited thrombin-mediated effects, including downstream activation of p38 MAPK, which in turn was required for Ang-2 expression. Conclusions The data establish an essential role of the Gab1/SHP2/p38MAPK signaling pathway and Ang-2 in regulating thrombin-induced monocyte adhesion and vascular leakage.
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Affiliation(s)
- K Rathnakumar
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences and Bioengineering, Indian Institute of Technology Madras, Chennai, India
| | - S Savant
- Division of Vascular Oncology and Metastasis, German Cancer Research Center Heidelberg (DKFZ-ZMBH Alliance), Heidelberg, Germany
| | - H Giri
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences and Bioengineering, Indian Institute of Technology Madras, Chennai, India
| | - A Ghosh
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences and Bioengineering, Indian Institute of Technology Madras, Chennai, India
| | - B Fisslthaler
- Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany
| | - I Fleming
- Institute for Vascular Signalling, Centre for Molecular Medicine, Goethe University, Frankfurt, Germany
| | - U Ram
- Seethapathy Clinic and Hospital, Chennai, India
| | - A K Bera
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences and Bioengineering, Indian Institute of Technology Madras, Chennai, India
| | - H G Augustin
- Division of Vascular Oncology and Metastasis, German Cancer Research Center Heidelberg (DKFZ-ZMBH Alliance), Heidelberg, Germany
- Vascular Biology and Tumor Angiogenesis, Medical Faculty Mannheim (CBTM), Heidelberg University, Heidelberg, Germany
| | - M Dixit
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences and Bioengineering, Indian Institute of Technology Madras, Chennai, India
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Zhou X, Weeks SD, Ameloot P, Callewaert N, Strelkov SV, Declerck PJ. Elucidation of the molecular mechanisms of two nanobodies that inhibit thrombin-activatable fibrinolysis inhibitor activation and activated thrombin-activatable fibrinolysis inhibitor activity. J Thromb Haemost 2016; 14:1629-38. [PMID: 27279497 DOI: 10.1111/jth.13381] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Indexed: 11/30/2022]
Abstract
UNLABELLED Essentials Thrombin-activatable fibrinolysis inhibitor (TAFI) is a risk factor for cardiovascular disorders. TAFI inhibitory nanobodies represent a promising step in developing profibrinolytic therapeutics. We have solved three crystal structures of TAFI in complex with inhibitory nanobodies. Nanobodies inhibit TAFI through distinct mechanisms and represent novel profibrinolytic leads. SUMMARY Background Thrombin-activatable fibrinolysis inhibitor (TAFI) is converted to activated TAFI (TAFIa) by thrombin, plasmin, or the thrombin-thrombomodulin complex (T/TM). TAFIa is antifibrinolytic, and high levels of TAFIa are associated with an increased risk for cardiovascular disorders. TAFI-inhibitory nanobodies represent a promising approach for developing profibrinolytic therapeutics. Objective To elucidate the molecular mechanisms of inhibition of TAFI activation and TAFIa activity by nanobodies with the use of X-ray crystallography and biochemical characterization. Methods and results We selected two nanobodies for cocrystallization with TAFI. VHH-a204 interferes with all TAFI activation modes, whereas VHH-i83 interferes with T/TM-mediated activation and also inhibits TAFIa activity. The 3.05-Å-resolution crystal structure of TAFI-VHH-a204 reveals that the VHH-a204 epitope is localized to the catalytic moiety (CM) in close proximity to the TAFI activation site at Arg92, indicating that VHH-a204 inhibits TAFI activation by steric hindrance. The 2.85-Å-resolution crystal structure of TAFI-VHH-i83 reveals that the VHH-i83 epitope is located close to the presumptive thrombomodulin-binding site in the activation peptide (AP). The structure and supporting biochemical assays suggest that VHH-i83 inhibits TAFIa by bridging the AP to the CM following TAFI activation. In addition, the 3.00-Å-resolution crystal structure of the triple TAFI-VHH-a204-VHH-i83 complex demonstrates that the two nanobodies can simultaneously bind to TAFI. Conclusions This study provides detailed insights into the molecular mechanisms of TAFI inhibition, and reveals a novel mode of TAFIa inhibition. VHH-a204 and VHH-i83 merit further evaluation as potential profibrinolytic therapeutics.
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Affiliation(s)
- X Zhou
- Department of Pharmaceutical and Pharmacologic Sciences, Laboratory for Therapeutic and Diagnostic Antibodies, KU Leuven, Belgium
| | - S D Weeks
- Department of Pharmaceutical and Pharmacologic Sciences, Laboratory for Biocrystallography, KU Leuven, Belgium
| | - P Ameloot
- Flanders Institute for Biotechnology, Medical Biotechnology Center, Ghent, Belgium
- Department of Biochemistry and Microbiology, Laboratory for Protein Biochemistry and Biomolecular Engineering, Ghent University, Ghent, Belgium
| | - N Callewaert
- Flanders Institute for Biotechnology, Medical Biotechnology Center, Ghent, Belgium
- Department of Biochemistry and Microbiology, Laboratory for Protein Biochemistry and Biomolecular Engineering, Ghent University, Ghent, Belgium
| | - S V Strelkov
- Department of Pharmaceutical and Pharmacologic Sciences, Laboratory for Biocrystallography, KU Leuven, Belgium
| | - P J Declerck
- Department of Pharmaceutical and Pharmacologic Sciences, Laboratory for Therapeutic and Diagnostic Antibodies, KU Leuven, Belgium
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Pezeshkpoor B, Castoldi E, Mahler A, Hanel D, Müller J, Hamedani NS, Biswas A, Oldenburg J, Pavlova A. Identification and functional characterization of a novel F5 mutation (Ala512Val, FVB onn ) associated with activated protein C resistance. J Thromb Haemost 2016; 14:1353-63. [PMID: 27090446 DOI: 10.1111/jth.13339] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Indexed: 11/29/2022]
Abstract
UNLABELLED Essentials Activated protein C (APC) resistance is a prevalent risk factor for venous thrombosis. A novel missense mutation (Ala512Val - FVBonn ) was characterized in vitro and in silico. FVBonn is a new cause of APC resistance and venous thrombosis. FVBonn expresses additionally enhanced procoagulant activity in the absence of APC. SUMMARY Background Activated protein C (APC) resistance is a prevalent risk factor for venous thrombosis. This phenotype is most commonly associated with the factor V Arg506Gln mutation (FV Leiden), which impairs the APC-mediated inactivation of both activated FV (FVa) and activated FVIII (FVIIIa). Objectives Here, we report the identification and characterization of a novel FV mutation (Ala512Val, FVBonn ) in six patients with APC resistance and venous thrombosis or recurrent abortions. Methods FVBonn was expressed in a recombinant system and compared with recombinant wild-type (WT) FV and FV Leiden in several functional assays. Results FVBonn conferred APC resistance to FV-depleted plasma, both in the activated partial thromboplastin time (APTT)-based test (APC sensitivity ratio [APCsr] of 1.98 for FVBonn versus 4.31 for WT FV and 1.59 for FV Leiden) and in the thrombin generation-based test (normalized APCsr of 5.41 for FVBonn versus 1.00 for WT FV and 8.99 for FV Leiden). The APC-mediated inactivation of FVaBonn was slower than that of WT FVa (mainly because of delayed cleavage at Arg506), but was greatly stimulated by protein S. The APC cofactor activity of FVBonn in FVIIIa inactivation was ~ 24% lower than that of WT FV. In line with these findings, an in silico analysis showed that the Ala512Val mutation is located in the same loop as the Arg506 APC cleavage site and might hamper its interaction with APC. Moreover, FVBonn was more procoagulant than WT FV and FV Leiden in the absence of APC, because of an increased activation rate and, possibly, an enhanced interaction with activated FX. Conclusions FVBonn induces hypercoagulability via a combination of increased activation/procoagulant activity, decreased susceptibility to APC-mediated inactivation, and slightly reduced APC cofactor activity.
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Affiliation(s)
- B Pezeshkpoor
- Institute of Experimental Hematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany
| | - E Castoldi
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands
| | | | - D Hanel
- Synlab MVZ, Stuttgart, Germany
| | - J Müller
- Institute of Experimental Hematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany
| | - N S Hamedani
- Institute of Experimental Hematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany
| | - A Biswas
- Institute of Experimental Hematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany
| | - J Oldenburg
- Institute of Experimental Hematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany
| | - A Pavlova
- Institute of Experimental Hematology and Transfusion Medicine, University Clinic Bonn, Bonn, Germany
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Rosenfeld MA, Bychkova AV, Shchegolikhin AN, Leonova VB, Kostanova EA, Biryukova MI, Sultimova NB, Konstantinova ML. Fibrin self-assembly is adapted to oxidation. Free Radic Biol Med 2016; 95:55-64. [PMID: 26969792 DOI: 10.1016/j.freeradbiomed.2016.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/29/2016] [Accepted: 03/07/2016] [Indexed: 10/22/2022]
Abstract
Fibrinogen is extremely susceptible to attack by reactive oxygen species (ROS). Having been suffered an oxidative modification, the fibrinogen molecules, now with altered spatial structure and function of fibrin network, affect hemostasis differently. However, the potential effects of the oxidative stress on the early stages of the fibrin self-assembly process remain unexplored. To clarify the damaging influence of ROS on the knob 'A': hole 'a' and the D:D interactions, the both are operating on the early stages of the fibrin polymerization, we have used a novel approach based on exploration of FXIIIa-mediated self-assembly of the cross-linked fibrin oligomers dissolved in the moderately concentrated urea solutions. The oligomers were composed of monomeric desA fibrin molecules created by cleaving the fibrinopeptides A off the fibrinogen molecules with a thrombin-like enzyme, reptilase. According to the UV-absorbance and fluorescence measurements data, the employed low ozone/fibrinogen ratios have induced only a slight fibrinogen oxidative modification that was accompanied by modest chemical transformations of the aromatic amino acid residues of the protein. Else, a slight consumption of the accessible tyrosine residues has been observed due to intermolecular dityrosine cross-links formation. The set of experimental data gathered with the aid of electrophoresis, elastic light scattering and analytical centrifugation has clearly witnessed that the oxidation can serve as an effective promoter for the observed enhanced self-assembly of the covalently cross-linked oligomers. At urea concentration of 1.20M, the pristine and oxidized fibrin oligomers were found to comprise a heterogeneous set of the double-stranded protofibrils that are cross-linked only by γ-γ dimers and the fibers consisting on average of four strands that are additionally linked by α polymers. The amounts of the oxidized protofibrils and the fibers accumulated in the system were higher than those of the non-oxidized counterparts. Moreover, the γ and α polypeptide chains of the oxidized molecules were more readily crosslinked by the FXIIIa. Upon increasing the urea solution concentration to 4.20M, the cross-linked double-stranded desA fibrin protofibrils have dissociated into the single-stranded fibrin oligomers, whereas the fibers dissociated into both the double-stranded desA fibrin oligomers, the structural integrity of the latter being maintained by means of the intermolecular α polymers, and the single-stranded fibrin oligomers cross-linked only by γ-γ dimers. The data we have obtained in this study indicate that the FXIIIa-mediated process of assembling the cross-linked protofibrils and the fibers constructed from the oxidized monomeric fibrin molecules was facilitated due to the strengthening of D:D interactions. The findings infer that the enhanced longitudinal D:D interactions become more essential in the assembly of soluble protofibrils when the interactions knobs 'A': holes 'a' are injured by oxidation. The new experimental findings presented here could be of help for elucidating the essential adaptive molecular mechanisms capable of mitigating the detrimental action of ROS in the oxidatively damaged fibrin self-assemblage processes.
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Affiliation(s)
- Mark A Rosenfeld
- N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4, Kosygina str., 119334 Moscow, Russia.
| | - Anna V Bychkova
- N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4, Kosygina str., 119334 Moscow, Russia
| | - Alexander N Shchegolikhin
- N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4, Kosygina str., 119334 Moscow, Russia
| | - Vera B Leonova
- N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4, Kosygina str., 119334 Moscow, Russia
| | - Elizaveta A Kostanova
- N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4, Kosygina str., 119334 Moscow, Russia
| | - Marina I Biryukova
- N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4, Kosygina str., 119334 Moscow, Russia
| | - Natalia B Sultimova
- N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4, Kosygina str., 119334 Moscow, Russia
| | - Marina L Konstantinova
- N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4, Kosygina str., 119334 Moscow, Russia
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Abstract
Platelets contain an abundance of growth factors that mimic the composition of the wound healing milieu, and platelet-derived VEGF in particular can negatively influence wound healing if unregulated. Here, we sought to capture and regulate the activity of VEGF factor from human platelets using poly(ethylene glycol) microspheres. In this communication, we demonstrate that platelet freeze/thaw produced significantly higher levels of Vascular Endothelial Growth Factor (VEGF) than either calcium chloride treatment, protease activated receptor 1 activating peptide (PAR1AP) treatment, or thrombin treatment. PEG microspheres containing a VEGF-binding peptide (VBP), derived from VEGFR2, sequestered VEGF from platelet concentrate, prepared via freeze/thaw, and reduced the bioactivity of platelet concentrate in HUVEC culture, which suggests that VBP microspheres sequestered and reduced the activity of VEGF from patient-derived platelets. Here, we demonstrate the ability of VEGF sequestering microspheres to regulate the activity of VEGF derived from a growth factor-rich autologous human blood product.
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Affiliation(s)
- David G. Belair
- Department of Biomedical Engineering, University of Wisconsin-Madison
| | - Ngoc Nhi Le
- Materials Science Program, University of Wisconsin-Madison
| | - William L. Murphy
- Department of Biomedical Engineering, University of Wisconsin-Madison
- Materials Science Program, University of Wisconsin-Madison
- Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison
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Monaghan M, Wakabayashi H, Griffiths AE, Fay PJ. Stabilizing interactions between D666-S1787 and T657-Y1792 at the A2-A3 interface support factor VIIIa stability in the blood clotting pathway. J Thromb Haemost 2016; 14:1021-30. [PMID: 26878264 PMCID: PMC4870127 DOI: 10.1111/jth.13292] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 01/20/2016] [Indexed: 12/01/2022]
Abstract
UNLABELLED Essentials Factor VIIIa (FVIIIa) is unstable due to loss of A2; D666 and Y1792 contribute to its stability. We conducted a study to identify the interactions made at these residues at the A2-A3 interface. We present evidence for stabilizing interactions between D666-S1787 and T657-Y1792 in FVIIIa. A D666C/S1788C variant with a disulfide A2-A3 linkage has a FVIIIa decay rate that is 1% of wild-type. SUMMARY Background Factor (F)VIIIa activity and stability depends on the non-covalent association of the A2 subunit with the A1/A3C1C2 dimer, but the interactions that contribute to A2 association are not well defined. Previous work had shown that D666A and Y1792F mutations at the A2-A3 interface resulted in increased FVIIIa decay, suggesting that the residues were involved in bonding interactions important for FVIIIa stability. Objectives Several potential hydrogen bonding partners of D666 and Y1792 across the A2-A3 interface were selected from the low-resolution FVIII crystal structure, and we used mutagenesis and biochemical analysis to examine the bonding interactions occurring at D666 and Y1792. Methods Using a series of stability and functional analyses, we analyzed FVIII variants in which D666 and Y1792 were each swapped with the residues of potential bonding partners. Results and conclusions We present evidence for hydrogen bonds between D666 and S1787 and between Y1792 and T657 that are important for FVIIIa stability. D666S/S1787D and T657Y/Y1792T variants each displayed wild-type (WT)-like FVIIIa stability and performed like WT FVIII in a series of functional analyses, whereas D666S, S1787D, and Y1792T single variants showed increased FVIIIa decay and a T657Y variant had little FVIIIa activity. These results suggest that WT hydrogen bonds are disrupted with the single mutations but maintained in the swap variants. Furthermore, mutation of D666 and S1788 to cysteine resulted in disulfide bond formation across the A2-A3 interface, confirming the close proximity of D666 and S1787, and this covalent attachment of the A2 subunit significantly increased FVIIIa stability.
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Affiliation(s)
- M Monaghan
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine, Rochester, NY 14642, USA
| | - H Wakabayashi
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine, Rochester, NY 14642, USA
| | - AE Griffiths
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine, Rochester, NY 14642, USA
| | - PJ Fay
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine, Rochester, NY 14642, USA
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Mooberry MJ, Bradford R, Hobl EL, Lin FC, Jilma B, Key NS. Procoagulant microparticles promote coagulation in a factor XI-dependent manner in human endotoxemia. J Thromb Haemost 2016; 14:1031-42. [PMID: 26857798 PMCID: PMC4870121 DOI: 10.1111/jth.13285] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Indexed: 11/30/2022]
Abstract
UNLABELLED Essentials The procoagulant effects of microparticles (MPs) on coagulation in endotoxemia are not known. MPs from endotoxemia volunteers were evaluated for procoagulant activity in a plasma milieu. MPs from endotoxemia volunteers shortened clotting times and enhanced thrombin generation. MP procoagulant effects were mediated in a factor XI-dependent manner. SUMMARY Background Human endotoxemia is characterized by acute inflammation and activation of coagulation, as well as increased numbers of circulating microparticles (MPs). Whether these MPs directly promote coagulation and through which pathway their actions are mediated, however, has not been fully explored. Objectives In this study, we aimed to further characterize endotoxin-induced MPs and their procoagulant properties using several approaches. Methods Enumeration and characterization of MPs were performed using a new-generation flow cytometer. Relative contributions of the extrinsic and intrinsic pathways in MP-mediated procoagulant activity were assessed using plasmas deficient in factor (F) VII or FXI or with blocking antibodies to tissue factor (TF) or FXIa. Results Total MPs and platelet MPs were significantly elevated in plasma at 6 h after infusion of endotoxin in healthy human subjects. MPs isolated from plasma following endotoxin infusion also demonstrated increased TF activity in a reconstituted buffer system. When added to recalcified platelet-poor plasma, these MPs also promoted coagulation, as judged by a decreased clotting time with shortening of the lag time and time to peak thrombin using calibrated automated thrombography (CAT). However, the use of FVII-deficient plasma or blocking antibody to TF did not inhibit these procoagulant effects. In contrast, plasma clotting time was prolonged in FXI-deficient plasma and a blocking antibody to FXIa inhibited all MP-mediated parameters in the CAT assay. Conclusions The initiation of coagulation by cellular TF in endotoxemia is in contrast to (and presumably complemented by) the intrinsic pathway-mediated procoagulant effects of circulating MPs.
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Affiliation(s)
- M J Mooberry
- Department of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - R Bradford
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA
| | - E L Hobl
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - F C Lin
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
| | - B Jilma
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - N S Key
- Department of Medicine, University of North Carolina, Chapel Hill, NC, USA
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA
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111
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Zamolodchikov D, Renné T, Strickland S. The Alzheimer's disease peptide β-amyloid promotes thrombin generation through activation of coagulation factor XII. J Thromb Haemost 2016; 14:995-1007. [PMID: 26613657 PMCID: PMC4870142 DOI: 10.1111/jth.13209] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 11/12/2015] [Indexed: 11/30/2022]
Abstract
UNLABELLED Essentials How the Alzheimer's disease (AD) peptide β-amyloid (Aβ) disrupts neuronal function in the disease is unclear. Factor (F) XII initiates blood clotting via FXI, and thrombosis has been implicated in AD. Aβ triggers FXII-dependent FXI and thrombin activation, evidence of which is seen in AD plasma. Aβ-triggered clotting could contribute to neuronal dysfunction in AD and be a novel therapeutic target. SUMMARY Background β-Amyloid (Aβ) is a key pathologic element in Alzheimer's disease (AD), but the mechanisms by which it disrupts neuronal function in vivo are not completely understood. AD is characterized by a prothrombotic state, which could contribute to neuronal dysfunction by affecting cerebral blood flow and inducing inflammation. The plasma protein factor XII triggers clot formation via the intrinsic coagulation cascade, and has been implicated in thrombosis. Objectives To investigate the potential for Aβ to contribute to a prothrombotic state. Methods and results We show that Aβ activates FXII, resulting in FXI activation and thrombin generation in human plasma, thereby establishing Aβ as a possible driver of prothrombotic states. We provide evidence for this process in AD by demonstrating decreased levels of FXI and its inhibitor C1 esterase inhibitor in AD patient plasma, suggesting chronic activation, inhibition and clearance of FXI in AD. Activation of the intrinsic coagulation pathway in AD is further supported by elevated fibrin levels in AD patient plasma. Conclusions The ability of Aβ to promote coagulation via the FXII-driven contact system identifies new mechanisms by which it could contribute to neuronal dysfunction and suggests potential new therapeutic targets in AD.
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Affiliation(s)
- Daria Zamolodchikov
- Patricia and John Rosenwald Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY 10065, USA
| | - Thomas Renné
- Division of Clinical Chemistry, Department of Molecular Medicine and Surgery, Karolinska Institutet and University Hospital, Stockholm S-171 76, Sweden
- Center of Molecular Medicine, Karolinska Institutet and University Hospital, Stockholm, Sweden
- Institute for Clinical Chemistry and Laboratory Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | - Sidney Strickland
- Patricia and John Rosenwald Laboratory of Neurobiology and Genetics, The Rockefeller University, New York, NY 10065, USA
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112
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Zhu S, Welsh JD, Brass LF, Diamond SL. Platelet-targeting thiol reduction sensor detects thiol isomerase activity on activated platelets in mouse and human blood under flow. J Thromb Haemost 2016; 14:1070-81. [PMID: 26725377 PMCID: PMC4870098 DOI: 10.1111/jth.13245] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 12/20/2015] [Indexed: 11/28/2022]
Abstract
UNLABELLED Essentials Protein disulfide isomerases may have an essential role in thrombus formation. A platelet-binding sensor (PDI-sAb) was developed to detect thiol reductase activity under flow. Primary human platelet adhesion to collagen at 200 s(-1) was correlated with the PDI-sAb signal. Detected thiol reductase activity was localized in the core of growing thrombi at the site of injury in mice. SUMMARY Background Protein disulfide isomerases (PDIs) may regulate thrombus formation in vivo, although the sources and targets of PDIs are not fully understood. Methods and results Using click chemistry to link anti-CD61 and a C-terminal azido disulfide-linked peptide construct with a quenched reporter, we developed a fluorogenic platelet-targeting antibody (PDI-sAb) for thiol reductase activity detection in whole blood under flow conditions. PDI-sAb was highly responsive to various exogenous reducing agents (dithiothreitol, glutathione and recombinant PDI) and detected thiol reductase activity on P-selectin/phosphatidylserine-positive platelets activated with convulxin/PAR1 agonist peptide, a signal partially blocked by PDI inhibitors and antibody. In a microfluidic thrombosis model using 4 μg mL(-1) corn trypsin inhibitor-treated human blood perfused over collagen (wall shear rate = 100 s(-1) ), the PDI-sAb signal increased mostly over the first 200 s, whereas platelets continually accumulated for over 500 s, indicating that primary adhesion to collagen, but not secondary aggregation, was correlated with the PDI-sAb signal. Rutin and the PDI blocking antibody RL90 reduced platelet adhesion and the PDI-sAb signal only when thrombin production was inhibited with PPACK, suggesting limited effects of platelet thiol isomerase activity on platelet aggregation on collagen in the presence of thrombin. With anti-mouse CD41 PDI-sAb used in an arteriolar laser injury model, thiol reductase activity was localized in the core of growing thrombi where platelets displayed P-selectin and were in close proximity to disrupted endothelium. Conclusion PDI-sAb is a sensitive and real-time reporter of platelet- and vascular-derived disulfide reduction that targets clots as they form under flow to reveal spatial gradients.
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Affiliation(s)
- S Zhu
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - J D Welsh
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, USA
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - L F Brass
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA
- Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - S L Diamond
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA
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113
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Berman DM, Molano RD, Fotino C, Ulissi U, Gimeno J, Mendez AJ, Kenyon NM, Kenyon NS, Andrews DM, Ricordi C, Pileggi A. Bioengineering the Endocrine Pancreas: Intraomental Islet Transplantation Within a Biologic Resorbable Scaffold. Diabetes 2016; 65:1350-61. [PMID: 26916086 PMCID: PMC5384628 DOI: 10.2337/db15-1525] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/17/2016] [Indexed: 12/15/2022]
Abstract
Transplantation of pancreatic islets is a therapeutic option to preserve or restore β-cell function. Our study was aimed at developing a clinically applicable protocol for extrahepatic transplantation of pancreatic islets. The potency of islets implanted onto the omentum, using an in situ-generated adherent, resorbable plasma-thrombin biologic scaffold, was evaluated in diabetic rat and nonhuman primate (NHP) models. Intraomental islet engraftment in the biologic scaffold was confirmed by achievement of improved metabolic function and preservation of islet cytoarchitecture, with reconstitution of rich intrainsular vascular networks in both species. Long-term nonfasting normoglycemia and adequate glucose clearance (tolerance tests) were achieved in both intrahepatic and intraomental sites in rats. Intraomental graft recipients displayed lower levels of serum biomarkers of islet distress (e.g., acute serum insulin) and inflammation (e.g., leptin and α2-macroglobulin). Importantly, low-purity (30:70% endocrine:exocrine) syngeneic rat islet preparations displayed function equivalent to that of pure (>95% endocrine) preparations after intraomental biologic scaffold implantation. Moreover, the biologic scaffold sustained allogeneic islet engraftment in immunosuppressed recipients. Collectively, our feasibility/efficacy data, along with the simplicity of the procedure and the safety of the biologic scaffold components, represented sufficient preclinical testing to proceed to a pilot phase I/II clinical trial.
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MESH Headings
- Animals
- Biocompatible Materials/adverse effects
- Biocompatible Materials/chemistry
- Biomarkers/blood
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/immunology
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Experimental/surgery
- Feasibility Studies
- Female
- Hyperglycemia/prevention & control
- Immunosuppression Therapy/adverse effects
- Islets of Langerhans/cytology
- Islets of Langerhans/ultrastructure
- Islets of Langerhans Transplantation/adverse effects
- Islets of Langerhans Transplantation/immunology
- Islets of Langerhans Transplantation/methods
- Islets of Langerhans Transplantation/pathology
- Macaca fascicularis
- Male
- Microscopy, Electron, Scanning
- Omentum
- Pancreas, Artificial/adverse effects
- Plasma/chemistry
- Plasma/metabolism
- Rats, Inbred Lew
- Rats, Inbred WF
- Recombinant Proteins/adverse effects
- Recombinant Proteins/chemistry
- Recombinant Proteins/metabolism
- Surface Properties
- Thrombin/adverse effects
- Thrombin/chemistry
- Thrombin/metabolism
- Tissue Engineering
- Tissue Scaffolds/adverse effects
- Tissue Scaffolds/chemistry
- Transplantation, Heterologous/adverse effects
- Transplantation, Heterotopic/adverse effects
- Transplantation, Isogeneic/adverse effects
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Affiliation(s)
- Dora M Berman
- Cell Transplant Center, Diabetes Research Institute, University of Miami, Miami, FL The DeWitt Daughtry Family Department of Surgery, University of Miami, Miami, FL
| | - R Damaris Molano
- Cell Transplant Center, Diabetes Research Institute, University of Miami, Miami, FL
| | - Carmen Fotino
- Cell Transplant Center, Diabetes Research Institute, University of Miami, Miami, FL
| | - Ulisse Ulissi
- Cell Transplant Center, Diabetes Research Institute, University of Miami, Miami, FL
| | - Jennifer Gimeno
- Cell Transplant Center, Diabetes Research Institute, University of Miami, Miami, FL
| | - Armando J Mendez
- Cell Transplant Center, Diabetes Research Institute, University of Miami, Miami, FL Department of Medicine, University of Miami, Miami, FL
| | - Norman M Kenyon
- Cell Transplant Center, Diabetes Research Institute, University of Miami, Miami, FL The DeWitt Daughtry Family Department of Surgery, University of Miami, Miami, FL
| | - Norma S Kenyon
- Cell Transplant Center, Diabetes Research Institute, University of Miami, Miami, FL The DeWitt Daughtry Family Department of Surgery, University of Miami, Miami, FL Department of Microbiology and Immunology, University of Miami, Miami, FL Department of Biomedical Engineering, University of Miami, Miami, FL
| | | | - Camillo Ricordi
- Cell Transplant Center, Diabetes Research Institute, University of Miami, Miami, FL The DeWitt Daughtry Family Department of Surgery, University of Miami, Miami, FL Department of Medicine, University of Miami, Miami, FL Department of Microbiology and Immunology, University of Miami, Miami, FL Department of Biomedical Engineering, University of Miami, Miami, FL
| | - Antonello Pileggi
- Cell Transplant Center, Diabetes Research Institute, University of Miami, Miami, FL The DeWitt Daughtry Family Department of Surgery, University of Miami, Miami, FL Department of Microbiology and Immunology, University of Miami, Miami, FL Department of Biomedical Engineering, University of Miami, Miami, FL
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114
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Wang W, Yuan J, Fu X, Meng F, Zhang S, Xu W, Xu Y, Huang C. Novel Anthranilamide-Based FXa Inhibitors: Drug Design, Synthesis and Biological Evaluation. Molecules 2016; 21:491. [PMID: 27089317 PMCID: PMC6274369 DOI: 10.3390/molecules21040491] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/31/2016] [Accepted: 04/07/2016] [Indexed: 01/26/2023] Open
Abstract
Factor Xa (FXa) plays a significant role in the blood coagulation cascade and it has become a promising target for anticoagulation drugs. Three oral direct FXa inhibitors have been approved by the FDA for treating thrombotic diseases. By structure-activity relationship (SAR) analysis upon these FXa inhibitors, a series of novel anthranilamide-based FXa inhibitors were designed and synthesized. According to our study, compounds 1a, 1g and 1s displayed evident FXa inhibitory activity and excellent selectivity over thrombin in in vitro inhibition activities studies. Compounds 1g and 1s also exhibited pronounced anticoagulant activities in in vitro anticoagulant activity studies.
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Affiliation(s)
- Wenzhi Wang
- School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China.
- Tianjin Key Laboratory of Molecular Design and Drug Discovery, Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China.
| | - Jing Yuan
- Tianjin Key Laboratory of Molecular Design and Drug Discovery, Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China.
| | - Xiaoli Fu
- Tianjin Key Laboratory of Molecular Design and Drug Discovery, Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China.
| | - Fancui Meng
- Tianjin Key Laboratory of Molecular Design and Drug Discovery, Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China.
| | - Shijun Zhang
- Tianjin Key Laboratory of Molecular Design and Drug Discovery, Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China.
| | - Weiren Xu
- Tianjin Key Laboratory of Molecular Design and Drug Discovery, Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China.
| | - Yongnan Xu
- School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, China.
| | - Changjiang Huang
- Tianjin Key Laboratory of Molecular Design and Drug Discovery, Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China.
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115
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Marar TT, Boffa MB. Identification of a thrombomodulin interaction site on thrombin-activatable fibrinolysis inhibitor that mediates accelerated activation by thrombin. J Thromb Haemost 2016; 14:772-83. [PMID: 26816270 DOI: 10.1111/jth.13275] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Indexed: 11/26/2022]
Abstract
BACKGROUND Thrombin-activatable fibrinolysis inhibitor (TAFI) is a human plasma zymogen that provides a molecular connection between coagulation and fibrinolysis. TAFI is activated through proteolytic cleavage by thrombin, thrombin in complex with the endothelial cell cofactor thrombomodulin (TM) or plasmin. Evidence from several studies suggests that TM and TAFI make direct contact at sites remote from the activating cleavage site to facilitate acceleration of thrombin-mediated TAFI activation. The elements of TAFI structure that allow accelerated activation of thrombin by TM are incompletely defined. OBJECTIVES To identify TM interaction regions on TAFI that mediate acceleration of activation by thrombin and therefore indicate TM binding sites on TAFI. METHODS We mutated selected surface-exposed charged residues on TAFI to alanine in order to identify sites that mediate acceleration of activation by TM. The kinetics of activation of the mutants by thrombin in the presence or absence of TM, as well as their thermal stabilities and antifibrinolytic potentials, were determined. RESULTS TAFI variants R15A, E28A, K59A, D75A/E77A/D78A, E99A and E106A all exhibited moderately reduced catalytic efficiencies of activation by thrombin-TM. TAFI variants R377A and, particularly, R12A and R12A/R15A exhibited severely reduced activation by thrombin-TM that was not explained by differences in activation by thrombin alone. CONCLUSIONS We have identified R12 as a critical residue for the activation of TAFI by thrombin-TM, extending a previous report that identified a role for this residue. R12 is likely to directly bind to TM while another key residue, R377, may affect the thrombin-TAFI interaction specifically in the presence of TM.
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Affiliation(s)
- T T Marar
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada
| | - M B Boffa
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, ON, Canada
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116
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Majoor CJ, Sneeboer MMS, de Kievit A, Meijers JCM, van der Poll T, Lutter R, Bel EH, Kamphuisen PW. The influence of corticosteroids on hemostasis in healthy subjects. J Thromb Haemost 2016; 14:716-23. [PMID: 26791678 DOI: 10.1111/jth.13265] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/07/2016] [Indexed: 11/26/2022]
Abstract
BACKGROUND Corticosteroids have been associated with an increased risk of venous thromboembolism in patients treated for inflammatory diseases. It is unclear whether the thrombotic risk is induced by the inflammation of the underlying inflammatory diseases or whether corticosteroids are prothrombotic as well. Considering the widespread use of corticosteroids in clinical practise, it is critical to know whether corticosteroids enhance coagulation. OBJECTIVE To investigate whether a 10-day prednisolone burst therapy activates hemostasis in healthy individuals. METHODS Healthy subjects received either 0.5 mg kg(-1) day(-1) of oral prednisolone or placebo. Venous blood was collected at baseline, day 1 and day 10 and tested for thrombin-antithrombin complexes (TATc), D-dimer, plasmin-alpha2-antiplasmin complexes (PAPc), plasminogen-activator inhibitor type-1 (PAI-1), von Willebrand factor (VWF) and thrombin generation (peak thrombin, velocity index and endogenous thrombin potential [ETP]). RESULTS Fifteen subjects received prednisolone and 16 placebo (median age 29 vs. 22 years, female subjects 33% vs. 56%, respectively). Peak thrombin and velocity index were higher in the placebo group at baseline. After 10 days of treatment, peak thrombin, velocity index, PAI-1 and VWF increased in the oral prednisolone group as compared with the placebo group (15.8 [SD 16.3] vs. -0.1 [SD 16.1], 41.2 [SD 41.3] vs. -2.3 [SD 42.7], 18.0 [IQR 8.0-37.0] vs. 0.5 [IQR -18.5-13.0], 4.0 [IQR -1.0-12.0] vs. 0.0 [IQR -2.5-1.5], respectively). No changes were observed for TATc, ETP, PAPc and D-dimer. CONCLUSIONS Oral prednisolone induces a procoagulant state in healthy subjects, suggesting that corticosteroid treatment may increase the thromboembolic risk in patients with inflammatory diseases.
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Affiliation(s)
- C J Majoor
- Department of Respiratory Medicine, Academic Medical Center, Amsterdam, the Netherlands
| | - M M S Sneeboer
- Department of Respiratory Medicine, Academic Medical Center, Amsterdam, the Netherlands
| | - A de Kievit
- Department of Respiratory Medicine, Academic Medical Center, Amsterdam, the Netherlands
| | - J C M Meijers
- Department of Experimental Vascular Medicine, Academic Medical Center, Amsterdam, the Netherlands
- Department of Plasma Proteins, Sanquin Research, Amsterdam, the Netherlands
| | - T van der Poll
- Center of Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, the Netherlands
| | - R Lutter
- Department of Respiratory Medicine, Academic Medical Center, Amsterdam, the Netherlands
- Department of Experimental Immunology, Academic Medical Center, Amsterdam, the Netherlands
| | - E H Bel
- Department of Respiratory Medicine, Academic Medical Center, Amsterdam, the Netherlands
| | - P W Kamphuisen
- Department of Vascular Medicine, University Medical Center Groningen, Groningen, the Netherlands
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117
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Abstract
Thrombin-activatable fibrinolysis inhibitor (TAFI) is an important regulator in the balance of coagulation and fibrinolysis. TAFI is a metallocarboxypeptidase that circulates in plasma as zymogen. Activated TAFI (TAFIa) cleaves C-terminal lysine or arginine residues from peptide substrates. The removal of C-terminal lysine residues from partially degraded fibrin leads to reduced plasmin formation and thus attenuation of fibrinolysis. TAFI also plays a role in inflammatory processes via the removal of C-terminal arginine or lysine residues from bradykinin, thrombin-cleaved osteopontin, C3a, C5a and chemerin. TAFI has been studied extensively over the past three decades and recent publications provide a wealth of information, including crystal structures, mutants and structural data obtained with antibodies and peptides. In this review, we combined and compared available data on structure/function relationships of TAFI.
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Affiliation(s)
- T Plug
- Department of Experimental Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - J C M Meijers
- Department of Experimental Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
- Department of Plasma Proteins, Sanquin Research, Amsterdam, the Netherlands
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118
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Mehta AY, Mohammed BM, Martin EJ, Brophy DF, Gailani D, Desai UR. Allosterism-based simultaneous, dual anticoagulant and antiplatelet action: allosteric inhibitor targeting the glycoprotein Ibα-binding and heparin-binding site of thrombin. J Thromb Haemost 2016; 14:828-38. [PMID: 26748875 PMCID: PMC4828251 DOI: 10.1111/jth.13254] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/24/2015] [Indexed: 12/01/2022]
Abstract
BACKGROUND Allosteric inhibition is a promising approach for developing a new group of anticoagulants with potentially reduced bleeding consequences. Recently, we designed sulfated β-O4 lignin (SbO4L) as an allosteric inhibitor that targets exosite 2 of thrombin to reduce fibrinogen cleavage through allostery and compete with glycoprotein Ibα to reduce platelet activation. OBJECTIVE To assess: (i) the antithrombotic potential of a novel approach of simultaneous exosite 2-dependent allosteric inhibition of thrombin and competitive inhibition of platelet activation; and (ii) the promise of SbO4L as the first-in-class antithrombotic agent. METHODS A combination of whole blood thromboelastography, hemostasis analysis, mouse arterial thrombosis models and mouse tail bleeding studies were used to assess antithrombotic potential. RESULTS AND CONCLUSIONS SbO4L extended the clot initiation time, and reduced maximal clot strength, platelet contractile force, and the clot elastic modulus, suggesting dual anticoagulant and antiplatelet effects. These effects were comparable to those observed with enoxaparin. A dose of 1 mg of SbO4L per mouse prevented occlusion in 100% of arteries, and lower doses resulted in a proportionally reduced response. Likewise, the time to occlusion increased by ~ 70% with a 0.5-mg dose in the mouse Rose Bengal thrombosis model. Finally, tail bleeding studies demonstrated that SbO4L does not increase bleeding propensity. In comparison, a 0.3-mg dose of enoxaparin increased the bleeding time and blood volume loss. Overall, this study highlights the promise of the allosteric inhibition approach, and presents SbO4L as a novel anticoagulant with potentially reduced bleeding side effects.
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Affiliation(s)
- Akul Y. Mehta
- Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23219, USA
| | - Bassem M. Mohammed
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA 23298, USA
- Department of Clinical Pharmacy, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
| | - Erika J. Martin
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Donald F. Brophy
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - David Gailani
- Department of Pathology, Immunology and Microbiology, Vanderbilt University Medical Center, Nashville, TN 37203
| | - Umesh R. Desai
- Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23219, USA
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119
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Siudut J, Grela M, Wypasek E, Plens K, Undas A. Reduced plasma fibrin clot permeability and susceptibility to lysis are associated with increased risk of postthrombotic syndrome. J Thromb Haemost 2016; 14:784-93. [PMID: 26786481 DOI: 10.1111/jth.13264] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Indexed: 12/31/2022]
Abstract
BACKGROUND The postthrombotic syndrome (PTS) is a severe complication of deep vein thrombosis (DVT). Reduced plasma clot permeability and lysability have been linked to DVT and residual vein obstruction. OBJECTIVES We investigated whether altered fibrin clot properties are associated with the occurrence of PTS. PATIENTS AND METHODS Plasma fibrin clot permeability (Ks ) and lysability were investigated in a cohort of 197 consecutive patients aged 18 to 65 years recruited 3 months following the first-ever DVT. Patients with severe thrombophilia or comorbidities known to adversely affect clot phenotype were ineligible. RESULTS During a 1-year follow-up PTS developed in 48 (24%) patients, who were characterized by lower Ks , prolonged fibrin clot lysis time (CLT) and slower release of D-dimer from clots (D-Drate ), together with higher plasma D-dimer, C-reactive protein and thrombin-activatable fibrinolysis inhibitor (TAFI). No PTS-associated differences in fibrinogen, thrombin generation, factor VIII, other fibrinolysis proteins and the quality of anticoagulation were observed. Ks (r = -0.71), CLT (r = 0.45), D-Drate (r = -0.30) and TAFI activity (r = 0.38) were associated with the Villalta scale (all P < 0.05). Recurrent VTE occurred also more commonly in PTS patients during follow-up and the 26 (13.2%) patients had lower Ks , longer CLT and lower D-Drate (all P < 0.05). A multivariate model adjusted for age, body mass index, fibrinogen and glucose showed that independent predictors of PTS were idiopathic DVT, plasma D-dimer, Ks , D-Drate , tissue plasminogen activator and TAFI activity. CONCLUSIONS This study demonstrates that formation of more compact fibrin clots displaying impaired susceptibility to lysis predisposes to PTS.
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Affiliation(s)
- J Siudut
- Krakow Centre for Medical Research and Technologies, John Paul II Hospital, Krakow, Poland
| | - M Grela
- Institute of Cardiology, Jagiellonian University Medical College, Krakow, Poland
| | - E Wypasek
- Institute of Cardiology, Jagiellonian University Medical College, Krakow, Poland
- Innovative Laboratory Diagnostic Center, John Paul II Hospital, Krakow, Poland
| | - K Plens
- Data Analysis Center, Krakow Cardiovascular Research Institute, Krakow, Poland
| | - A Undas
- Krakow Centre for Medical Research and Technologies, John Paul II Hospital, Krakow, Poland
- Institute of Cardiology, Jagiellonian University Medical College, Krakow, Poland
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Martinelli N, Girelli D, Baroni M, Guarini P, Sandri M, Lunghi B, Tosi F, Branchini A, Sartori F, Woodhams B, Bernardi F, Olivieri O. Activated factor VII-antithrombin complex predicts mortality in patients with stable coronary artery disease: a cohort study. J Thromb Haemost 2016; 14:655-66. [PMID: 27061056 DOI: 10.1111/jth.13274] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 01/12/2016] [Indexed: 01/06/2023]
Abstract
BACKGROUND Plasma concentration of activated factor VII (FVIIa)-antithrombin (AT) complex has been proposed as an indicator of intravascular exposure of tissue factor. OBJECTIVES The aims of this observational study were to evaluate (i) FVIIa-AT plasma concentration in subjects with or without coronary artery disease (CAD) and (ii) its association with mortality in a prospective cohort of patients with CAD. METHODS FVIIa-AT levels were measured by elisa in 686 subjects with (n = 546) or without (n = 140) angiographically proven CAD. Subjects with acute coronary syndromes and those taking anticoagulant drugs at the time of enrollment were excluded. CAD patients were followed for total and cardiovascular mortality. RESULTS There was no difference in FVIIa-AT levels between CAD (84.8 with 95% confidence interval [CI] 80.6-88.2 pmol L(-1) ) and CAD-free subjects (83.9 with 95% CI 76.7-92.8 pmol L(-1) ). Within the CAD population, during a 64-month median follow-up, patients with FVIIa-AT levels higher than the median value at baseline (≥ 79 pmol L(-1) ) had a two-fold greater risk of both total and cardiovascular mortality. Results were confirmed after adjustment for sex, age, the other predictors of mortality (hazard ratio for total mortality: 2.05 with 95% CI 1.22-3.45, hazard ratio for cardiovascular mortality 1.94 with 95% CI 1.01-3.73, with a slight improvement of C-statistic over traditional risk factors), FVIIa levels, drug therapy at discharge, and even patients using all the usual medications for CAD treatment. High FVIIa-AT levels also correlated with increased thrombin generation. CONCLUSIONS This preliminary study suggests that plasma concentration of FVIIa-AT is a thrombophilic marker of total and cardiovascular mortality risk in patients with clinically stable CAD.
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Affiliation(s)
- N Martinelli
- Department of Medicine, University of Verona, Verona, Italy
| | - D Girelli
- Department of Medicine, University of Verona, Verona, Italy
| | - M Baroni
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - P Guarini
- Department of Medicine, University of Verona, Verona, Italy
| | - M Sandri
- Department of Medicine, University of Verona, Verona, Italy
| | - B Lunghi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - F Tosi
- Department of Medicine, University of Verona, Verona, Italy
| | - A Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - F Sartori
- Department of Medicine, University of Verona, Verona, Italy
| | | | - F Bernardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - O Olivieri
- Department of Medicine, University of Verona, Verona, Italy
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Cui C, Park DH, Choi H, Joo J, Ahn DJ. Protein Recognition by Phase Transition of Aptamer-Linked Polythiophene Single Nanowire. Small 2016; 12:1154-1158. [PMID: 26651134 DOI: 10.1002/smll.201501908] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 11/09/2015] [Indexed: 06/05/2023]
Abstract
A novel protein recognition platform is developed using aptamer-linked polythiophene nanowires. As the aptamer functionalized poly (3-methylthiophene) nanowire is treated by the specific protein, resonance Raman and photoluminescence signals are simultaneously enhanced. Statistical analyses deliver the capability of a single conjugated polymer nanowire with phase-transition characteristics in response to selectivity and concentration.
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Affiliation(s)
- Chunzhi Cui
- Department of Chemical and Biological Engineering, Korea University, Seoul, 136-701, Korea
| | - Dong Hyuk Park
- Department of Applied Organic Materials Engineering, Inha University, Incheon, 402-751, Korea
| | - Hyun Choi
- Department of Chemical and Biological Engineering, Korea University, Seoul, 136-701, Korea
| | - Jinsoo Joo
- Department of Physics, Korea University, Seoul, 136-713, Korea
| | - Dong June Ahn
- Department of Chemical and Biological Engineering, Korea University, Seoul, 136-701, Korea
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul, 136-701, Korea
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Bhat R, Ribes À, Mas N, Aznar E, Sancenón F, Marcos MD, Murguía JR, Venkataraman A, Martínez-Máñez R. Thrombin-Responsive Gated Silica Mesoporous Nanoparticles As Coagulation Regulators. Langmuir 2016; 32:1195-1200. [PMID: 26794474 DOI: 10.1021/acs.langmuir.5b04038] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The possibility of achieving sophisticated actions in complex biological environments using gated nanoparticles is an exciting prospect with much potential. We herein describe new gated mesoporous silica nanoparticles (MSN) loaded with an anticoagulant drug and capped with a peptide containing a thrombin-specific cleavage site. When the coagulation cascade was triggered, active thrombin degraded the capping peptidic sequence and induced the release of anticoagulant drugs to delay the clotting process. The thrombin-dependent response was assessed and a significant increase in coagulation time in plasma from 2.6 min to 5 min was found. This work broadens the application of gated silica nanoparticles and demonstrates their ability to act as controllers in a complex scenario such as hemostasis.
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Affiliation(s)
- Ravishankar Bhat
- Materials Chemistry Laboratory, Department of Materials Science and Department of Chemistry, Gulbarga University , Gulbarga-585106, India
| | - Àngela Ribes
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) , Valencia, Spain
| | - Núria Mas
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) , Valencia, Spain
| | - Elena Aznar
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) , Valencia, Spain
| | - Félix Sancenón
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) , Valencia, Spain
| | - M Dolores Marcos
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) , Valencia, Spain
| | - Jose R Murguía
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) , Valencia, Spain
| | - Abbaraju Venkataraman
- Materials Chemistry Laboratory, Department of Materials Science and Department of Chemistry, Gulbarga University , Gulbarga-585106, India
| | - Ramón Martínez-Máñez
- CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN) , Valencia, Spain
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Ustyuzhanina NE, Bilan MI, Gerbst AG, Ushakova NA, Tsvetkova EA, Dmitrenok AS, Usov AI, Nifantiev NE. Anticoagulant and antithrombotic activities of modified xylofucan sulfate from the brown alga Punctaria plantaginea. Carbohydr Polym 2016; 136:826-33. [PMID: 26572418 DOI: 10.1016/j.carbpol.2015.09.102] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 09/23/2015] [Accepted: 09/26/2015] [Indexed: 01/08/2023]
Abstract
Selectively and totally sulfated (1 → 3)-linked linear homofucans bearing ∼ 20 monosaccharide residues on average have been prepared from the branched xylofucan sulfate isolated from the brown alga Punctaria plantaginea. Anticoagulant and antithrombotic properties of the parent biopolymer and its derivatives were assessed in vitro. Highly sulfated linear fucan derivatives were shown to inhibit clot formation in APTT assay and ristocetin induced platelets aggregation, while the partially sulfated analogs were inactive. In the experiments with purified proteins, fucan derivatives with degree of sulfation of ∼ 2.0 were found to enhance thrombin and factor Xa inhibition by antithrombin III. The effect of sulfated fucans on thrombin inhibition, which was similar to those of heparinoid Clexane(®) (enoxaparin) and of a fucoidan from the brown alga Saccharina latissima studied previously, can be explained by the multicenter interaction and formation of a ternary complex thrombin-antithrombin III-polysaccharide. The possibility of such complexation was confirmed by computer docking study.
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Affiliation(s)
- Nadezhda E Ustyuzhanina
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, B-334, 119991 Moscow, Russian Federation
| | - Maria I Bilan
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, B-334, 119991 Moscow, Russian Federation
| | - Alexey G Gerbst
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, B-334, 119991 Moscow, Russian Federation
| | - Natalia A Ushakova
- V.N. Orekhovich Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, Pogodinskaya Str. 10, 119121 Moscow, Russian Federation
| | - Eugenia A Tsvetkova
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, B-334, 119991 Moscow, Russian Federation
| | - Andrey S Dmitrenok
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, B-334, 119991 Moscow, Russian Federation
| | - Anatolii I Usov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, B-334, 119991 Moscow, Russian Federation
| | - Nikolay E Nifantiev
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky Prospect 47, B-334, 119991 Moscow, Russian Federation.
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Baglin TP, Langdown J, Frasson R, Huntington JA. Discovery and characterization of an antibody directed against exosite I of thrombin. J Thromb Haemost 2016; 14:137-42. [PMID: 26469093 DOI: 10.1111/jth.13171] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/03/2015] [Indexed: 11/28/2022]
Abstract
UNLABELLED ESSENTIALS: An IgA paraprotein with anti-thrombin activity was not associated with a severe bleeding phenotype. This observation challenges the paradigm that anticoagulant therapy necessarily increases bleeding risk. Characterization of the antibody showed that it specifically binds to thrombin exosite I. A therapeutic drug with the properties of this antibody might be an antithrombotic that doesn't cause bleeding. BACKGROUND We report the case of a 54-year-old female who presented with a traumatic subdural hemorrhage. Coagulation tests were markedly prolonged due to the presence of an anti-thrombin IgA paraprotein at 3 g L(-1) . The patient made a complete recovery and has had no abnormal bleeding during a 7-year follow-up, despite the persistence of the paraprotein. OBJECTIVES To determine how the paraprotein prolonged clotting tests by defining its target and its epitope. METHODS The paraprotein was purified and added to normal pooled plasma for in vitro clotting assays. Binding studies were conducted to determine the affinity of the IgA for thrombin. The Fab was isolated and crystallized with thrombin. RESULTS The purified IgA was sufficient to confer the patient's in vitro coagulation profile in normal pooled plasma, and was found to bind specifically and with high affinity to thrombin. A crystal structure of the Fab fragment in complex with thrombin revealed an exosite I interaction involving CDRH3 of the antibody. CONCLUSIONS Although the patient originally presented with a subdural bleed, the hematoma resolved without intervention, and no other bleeding event occurred during the subsequent 7 years. During this period, the patient's IgA paraprotein levels have remained constant at 3 g L(-1) , suggesting that the presence of a high-affinity, exosite I-directed antibody is consistent with normal hemostasis. A therapeutic derivative of this antibody might therefore permit antithrombotic dose escalation without an associated increase in the risk of bleeding.
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Affiliation(s)
- T P Baglin
- Department of Haematology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Trust, Cambridge, UK
| | - J Langdown
- Department of Haematology, Addenbrooke's Hospital, Cambridge University Hospitals NHS Trust, Cambridge, UK
| | - R Frasson
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
| | - J A Huntington
- Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
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Mena-Ulecia K, Tiznado W, Caballero J. Study of the Differential Activity of Thrombin Inhibitors Using Docking, QSAR, Molecular Dynamics, and MM-GBSA. PLoS One 2015; 10:e0142774. [PMID: 26599107 PMCID: PMC4657979 DOI: 10.1371/journal.pone.0142774] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/27/2015] [Indexed: 11/18/2022] Open
Abstract
Non-peptidic thrombin inhibitors (TIs; 177 compounds) with diverse groups at motifs P1 (such as oxyguanidine, amidinohydrazone, amidine, amidinopiperidine), P2 (such as cyanofluorophenylacetamide, 2-(2-chloro-6-fluorophenyl)acetamide), and P3 (such as phenylethyl, arylsulfonate groups) were studied using molecular modeling to analyze their interactions with S1, S2, and S3 subsites of the thrombin binding site. Firstly, a protocol combining docking and three dimensional quantitative structure-activity relationship was performed. We described the orientations and preferred active conformations of the studied inhibitors, and derived a predictive CoMSIA model including steric, donor hydrogen bond, and acceptor hydrogen bond fields. Secondly, the dynamic behaviors of some selected TIs (compounds 26, 133, 147, 149, 162, and 177 in this manuscript) that contain different molecular features and different activities were analyzed by creating the solvated models and using molecular dynamics (MD) simulations. We used the conformational structures derived from MD to accomplish binding free energetic calculations using MM-GBSA. With this analysis, we theorized about the effect of van der Waals contacts, electrostatic interactions and solvation in the potency of TIs. In general, the contents reported in this article help to understand the physical and chemical characteristics of thrombin-inhibitor complexes.
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Affiliation(s)
- Karel Mena-Ulecia
- Departamento de Química, Facultad de Ciencias Exactas, Universidad Andres Bello, Avenida República 252, Santiago, Chile
- Centro de Bioinformática y Simulación Molecular, Facultad de Ingeniería, Universidad de Talca, 2 Norte 685, Casilla 721, Talca, Chile
| | - William Tiznado
- Departamento de Química, Facultad de Ciencias Exactas, Universidad Andres Bello, Avenida República 252, Santiago, Chile
| | - Julio Caballero
- Centro de Bioinformática y Simulación Molecular, Facultad de Ingeniería, Universidad de Talca, 2 Norte 685, Casilla 721, Talca, Chile
- * E-mail: or
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126
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Einfinger K, Badrnya S, Furtmüller M, Handschuh D, Lindner H, Geiger M. Phospholipid Binding Protein C Inhibitor (PCI) Is Present on Microparticles Generated In Vitro and In Vivo. PLoS One 2015; 10:e0143137. [PMID: 26580551 PMCID: PMC4651509 DOI: 10.1371/journal.pone.0143137] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/31/2015] [Indexed: 12/11/2022] Open
Abstract
Protein C inhibitor is a secreted, non-specific serine protease inhibitor with broad protease reactivity. It binds glycosaminoglycans and anionic phospholipids, which can modulate its activity. Anionic phospholipids, such as phosphatidylserine are normally localized to the inner leaflet of the plasma membrane, but are exposed on activated and apoptotic cells and on plasma membrane-derived microparticles. In this report we show by flow cytometry that microparticles derived from cultured cells and activated platelets incorporated protein C inhibitor during membrane blebbing. Moreover, protein C inhibitor is present in/on microparticles circulating in normal human plasma as judged from Western blots, ELISAs, flow cytometry, and mass spectrometry. These plasma microparticles are mainly derived from megakaryocytes. They seem to be saturated with protein C inhibitor, since they do not bind added fluorescence-labeled protein C inhibitor. Heparin partially removed microparticle-bound protein C inhibitor, supporting our assumption that protein C inhibitor is bound via phospholipids. To assess the biological role of microparticle-bound protein C inhibitor we performed protease inhibition assays and co-precipitated putative binding partners on microparticles with anti-protein C inhibitor IgG. As judged from amidolytic assays microparticle-bound protein C inhibitor did not inhibit activated protein C or thrombin, nor did microparticles modulate the activity of exogenous protein C inhibitor. Among the proteins co-precipitating with protein C inhibitor, complement factors, especially complement factor 3, were most striking. Taken together, our data do not support a major role of microparticle-associated protein C inhibitor in coagulation, but rather suggest an interaction with proteins of the complement system present on these phospholipid vesicles.
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Affiliation(s)
- Katrin Einfinger
- Center of Physiology and Pharmacology, Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Sigrun Badrnya
- Center of Physiology and Pharmacology, Department of Physiology, Medical University of Vienna, Vienna, Austria
| | - Margareta Furtmüller
- Center of Physiology and Pharmacology, Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Daniela Handschuh
- Center of Physiology and Pharmacology, Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
| | - Herbert Lindner
- Biocenter, Division of Clinical Biochemistry, Innsbruck Medical University, Innsbruck, Austria
| | - Margarethe Geiger
- Center of Physiology and Pharmacology, Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Vienna, Austria
- * E-mail:
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Leung KH, He B, Yang C, Leung CH, Wang HMD, Ma DL. Development of an Aptamer-Based Sensing Platform for Metal Ions, Proteins, and Small Molecules through Terminal Deoxynucleotidyl Transferase Induced G-Quadruplex Formation. ACS Appl Mater Interfaces 2015; 7:24046-52. [PMID: 26449329 DOI: 10.1021/acsami.5b08314] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report a label-free, structure-independent luminescent-sensing platform for metal ions, proteins, and small molecules utilizing an Ir(III) complex, terminal deoxynucleotidyl transferase (TdT), and a structure-folding aptamer. A novel G-quadruplex-selective Ir(III) complex was identified to detect the nascent G-quadruplex motifs with an enhanced luminescence response. Unlike most label-free DNA-based assays reported in the literature, this sensing platform does not require a specific secondary structure of aptamer, thus greatly simplifying DNA design. The detection platform was demonstrated by the detection of K(+) ions, thrombin, and cocaine as representative examples of metal ions, proteins, and small molecules.
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Affiliation(s)
| | | | - Chao Yang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau , Macao, China
| | - Chung-Hang Leung
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau , Macao, China
| | - Hui-Min David Wang
- Graduate Institute of Natural Products, Kaohsiung Medical University , Kaohsiung 807, Taiwan
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128
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Zhao D, Peng Y, Xu L, Zhou W, Wang Q, Guo L. Liquid-Crystal Biosensor Based on Nickel-Nanosphere-Induced Homeotropic Alignment for the Amplified Detection of Thrombin. ACS Appl Mater Interfaces 2015; 7:23418-22. [PMID: 26458050 DOI: 10.1021/acsami.5b08924] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A new liquid-crystal (LC)-based sensor operated by nickel nanosphere (NiNS)-induced homeotropic alignment for the label-free monitoring of thrombin was reported. When doped with NiNSs, a uniform vertical orientation of 4-cyano-4'-pentylbiphenyl (5CB) was easily obtained. A sandwich system of aptamer/thrombin/aptamer-functionalized gold nanoparticles (AuNPs) was fabricated, and AuNPs-aptamer conjugation caused the disruption of the 5CB orientation, leading to an obvious change of the optical appearance from a dark to a bright response to thrombin concentrations from 0.1 to 100 nM. This design also allowed quantitative detection of the thrombin concentration. This distinctive and sensitive thrombin LC sensor provides a new principle for building LC-sensing systems.
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Affiliation(s)
- Dongyu Zhao
- School of Chemistry and Environment Science, Beijing University of Aeronautics and Astronautics , Beijing 100191, China
| | - Yi Peng
- School of Chemistry and Environment Science, Beijing University of Aeronautics and Astronautics , Beijing 100191, China
| | - Lihong Xu
- School of Chemistry and Environment Science, Beijing University of Aeronautics and Astronautics , Beijing 100191, China
| | - Wei Zhou
- School of Chemistry and Environment Science, Beijing University of Aeronautics and Astronautics , Beijing 100191, China
| | - Qian Wang
- School of Chemistry and Environment Science, Beijing University of Aeronautics and Astronautics , Beijing 100191, China
| | - Lin Guo
- School of Chemistry and Environment Science, Beijing University of Aeronautics and Astronautics , Beijing 100191, China
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Vivas-Ruiz D, Sandoval GA, Lazo F, Rodríguez E, Yarlequé A, Flores-Sánchez E. [Characterization of thrombin like enzyme FROM Bothrops pictus venom]. Rev Peru Med Exp Salud Publica 2015; 32:652-658. [PMID: 26732911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 06/17/2015] [Indexed: 06/05/2023] Open
Abstract
OBJECTIVES To perform a biochemical and molecular characterization of the coagulant principle from Bothrops pictus venom. MATERIALS AND METHODS We amplified the genetic sequence of this enzyme from cDNA and analyzed the homology of its nucleotide sequence and its deduced protein. This enzyme was also purified for N-terminal sequencing of first 20 amino acids and for coagulation assays using human plasma and human fibrinogen. Furthermore, cleavage pattern on fibrinogen was evaluated using SDS-PAGE and defibrinogenant activity on white mice (18-22 g). Finally, associated carbohydrate content, effect of protease inhibitors and chloride ions on its enzymatic activity were analyzed. RESULTS The Thrombin-like Enzyme from Bothrops pictus showed homology at primary level of structure with other previously reported TLEs from Viperidae family. Minimum Coagulant Dosis (MCD) on plasma and human fibrinogen were 18 and 6 µg, respectively, and its coagulant potency was 131.1 NHI Thrombin units. This TLE was stable under physiological conditions and chloride ions are not necessary for its activity. Detected associated carbohydrates were hexoses (25.76%), hexosamines (13.12%) and sialic acid (0.76%). Phenyl methyl sulphonyl fluoride (PMSF) and dithiothreitol (DTT) were the main inhibitors of its enzymatic activity, but heparin had no inhibitor effect. CONCLUSIONS The coagulant principle of Bothrops pictus venom is a Thrombin-like enzyme.
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Affiliation(s)
- Dan Vivas-Ruiz
- Laboratorio de Biología Molecular, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Perú
| | - Gustavo A Sandoval
- Laboratorio de Biología Molecular, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Perú
| | - Fanny Lazo
- Laboratorio de Biología Molecular, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Perú
| | - Edith Rodríguez
- Laboratorio de Biología Molecular, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Perú
| | - Armando Yarlequé
- Laboratorio de Biología Molecular, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Perú
| | - Eladio Flores-Sánchez
- Laboratorio de Bioquímica y Química de Proteínas, Fundación Ezequiel Días, Bello Horizonte Brasil, Bello Horizonte, Brasil
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Abstract
Prothrombin is activated to thrombin by the prothrombinase complex through sequential cleavage at two distinct sites. This occurs at sites of vascular injury in a highly regulated cascade of serine protease and cofactor activation, where activated platelets provide a suitable surface for protease/cofactor/substrate assembly. The precise structural and conformational changes undergone during the transition from prothrombin to thrombin have been studied for decades, and several structures of prothrombin fragments along the activation pathway have been solved. Here we present a new structure analyzed in context of other recent structures and biochemical studies. What emerges is an unexpected mechanism that involves a change in the mode of binding of the F2 domain (fragment 2) on the catalytic domain after cleavage at Arg320, and a subsequent reorientation of the linker between the F2 and catalytic domain to present the Arg271 site for cleavage. The catalytic domain of thrombin precursors binds to its F2 domain by two distinct modes. Cleavage of prothrombin at either Arg271 or Arg320 results in shift from mode 2 to mode 1. After cleavage at Arg320, movement of F2 helps to present the second cleavage site at Arg271.
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Affiliation(s)
- Ty E Adams
- Cambridge Institute for Medical Research, Department of Haematology, University of Cambridge, Wellcome Trust/MRC Building, Hills Road, Cambridge, CB2 0XY, United Kingdom
| | - James A Huntington
- Cambridge Institute for Medical Research, Department of Haematology, University of Cambridge, Wellcome Trust/MRC Building, Hills Road, Cambridge, CB2 0XY, United Kingdom.
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131
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Sokolov AV, Acquasaliente L, Kostevich VA, Frasson R, Zakharova ET, Pontarollo G, Vasilyev VB, De Filippis V. Thrombin inhibits the anti-myeloperoxidase and ferroxidase functions of ceruloplasmin: relevance in rheumatoid arthritis. Free Radic Biol Med 2015; 86:279-94. [PMID: 26001728 DOI: 10.1016/j.freeradbiomed.2015.05.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 04/24/2015] [Accepted: 05/12/2015] [Indexed: 01/29/2023]
Abstract
Human ceruloplasmin (CP) is a multifunctional copper-binding protein produced in the liver. CP oxidizes Fe(2+) to Fe(3+), decreasing the concentration of Fe(2+) available for generating harmful oxidant species. CP is also a potent inhibitor of leukocyte myeloperoxidase (MPO) (Kd=130nM), a major source of oxidants in vivo. Rheumatoid arthritis (RA) is an inflammatory autoimmune disease affecting flexible joints and characterized by activation of both inflammatory and coagulation processes. Indeed, the levels of CP, MPO, and thrombin are markedly increased in the synovial fluid of RA patients. Here we show that thrombin cleaves CP in vitro at (481)Arg-Ser(482) and (887)Lys-Val(888) bonds, generating a nicked species that retains the native-like fold and the ferroxidase activity of the intact protein, whereas the MPO inhibitory function of CP is abrogated. Analysis of the synovial fluid of 24 RA patients reveals that CP is proteolytically degraded to a variable extent, with a fragmentation pattern similar to that observed with thrombin in vitro, and that proteolysis is blocked by hirudin, a highly potent and specific thrombin inhibitor. Using independent biophysical techniques, we show that thrombin has intrinsic affinity for CP (Kd=60-270nM), independent of proteolysis, and inhibits CP ferroxidase activity (KI=220±20nM). Mapping of thrombin binding sites with specific exosite-directed ligands (i.e., hirugen, fibrinogen γ'-peptide) and thrombin analogues having the exosites variably compromised (i.e., prothrombin, prethrombin-2, βT-thrombin) reveals that the positively charged exosite-II of thrombin binds to the negatively charged upper region of CP, while the protease active site and exosite-I remain accessible. These results suggest that thrombin can exacerbate inflammation in RA by impairing the MPO inhibitory function of CP via proteolysis and by competitively inhibiting CP ferroxidase activity. Notably, local administration of hirudin, a highly potent and specifc thrombin inhibitor, reduces the concentration of active MPO in the synovial fluid of RA patients and has a beneficial effect on the clinical symptoms of the disease.
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Affiliation(s)
- Alexej V Sokolov
- Institute for Experimental Medicine, Pavlov str., 12, Saint Petersburg, 197376 Russia; State University of Saint Petersburg, University Embankment, 4-7, Saint Petersburg, 199034 Russia
| | - Laura Acquasaliente
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, via Marzolo, 5, Padua, 35131 Italy
| | - Valeria A Kostevich
- Institute for Experimental Medicine, Pavlov str., 12, Saint Petersburg, 197376 Russia
| | - Roberta Frasson
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, via Marzolo, 5, Padua, 35131 Italy
| | - Elena T Zakharova
- Institute for Experimental Medicine, Pavlov str., 12, Saint Petersburg, 197376 Russia
| | - Giulia Pontarollo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, via Marzolo, 5, Padua, 35131 Italy
| | - Vadim B Vasilyev
- Institute for Experimental Medicine, Pavlov str., 12, Saint Petersburg, 197376 Russia; State University of Saint Petersburg, University Embankment, 4-7, Saint Petersburg, 199034 Russia
| | - Vincenzo De Filippis
- Department of Pharmaceutical and Pharmacological Sciences, University of Padua, via Marzolo, 5, Padua, 35131 Italy.
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Liu X, Hua X, Fan Q, Chao J, Su S, Huang YQ, Wang L, Huang W. Thioflavin T as an Efficient G-Quadruplex Inducer for the Highly Sensitive Detection of Thrombin Using a New Föster Resonance Energy Transfer System. ACS Appl Mater Interfaces 2015; 7:16458-16465. [PMID: 26173915 DOI: 10.1021/acsami.5b03662] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report a new Föster resonance energy transfer (FRET) system that uses a special dye, thioflavin T (ThT), as an energy acceptor and a water-soluble conjugated polymer (CP) with high fluorescence as an energy donor. A simple, label-free, and sensitive strategy for the detection of thrombin in buffer and in diluted serum was designed based on this new system using ThT as an efficient inducer of the G-quadruplex. The difference between the blank and the positive samples was amplified due to distinctive FRET signals because thrombin has little effect on the intercalation of ThT into the G-quadruplex. In the absence of the target, ThT induces the aptamer to form a G-quadruplex and intercalates into it with strong fluorescence. The electrostatic attractions between the negatively charged G-quadruplex and positively charged CP allow a short donor-acceptor distance, resulting in a high FRET signal. However, in the presence of the target, the aptamer forms a G-quadruplex-thrombin complex first, followed by the intercalation of ThT into the G-quadruplex. A long distance exists between the donor and acceptor due to the strong steric hindrance from the large-sized thrombin, which leads to a low FRET signal. Compared with previously reported strategies based on the FRET between the CP and dye, our strategy is label-free, and the sensitivity was improved by an order of magnitude. Our strategy also shows the advantages of being simple, rapid (about 50 min), sensitive, label-free, and low-cost in comparison to strategies based on the FRET between quantum dots and dyes.
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133
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Liu SH, Huang SF, Hsu YL, Pan SH, Chen YJ, Lin YH. Structure of human collapsin response mediator protein 1: a possible role of its C-terminal tail. Acta Crystallogr F Struct Biol Commun 2015; 71:938-45. [PMID: 26249678 PMCID: PMC4528920 DOI: 10.1107/s2053230x15009243] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 05/15/2015] [Indexed: 11/11/2022] Open
Abstract
Collapsin response mediator protein 1 (CRMP-1) is the first identified member of the CRMP family and is crucial for both the mediation of neuronal differentiation and in suppressing the invasion of lung cancer. The crystal structure of full-length human CRMP-1 was determined at a resolution of 3 Å. Human CRMP-1 comprises a tetrameric assembly; its overall structure is similar to that of mouse CRMP-1, but the measured electron density of the C-terminal residues 488-496 show a randomly coiled link that connects the protomers to each other, within which residues 497-572 are proteolytically susceptible in vivo. Deletion of residues 472-572 by thrombin in vitro not only releases a randomly coiled tail but also transduces observable structural changes of CRMP-1, as revealed by analytical size-exclusive chromatography and circular dichroism spectra. These results indicate a possible alternative role in CRMP dynamics and function.
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Affiliation(s)
- Szu-Heng Liu
- Life science group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
- National Institute of Cancer Research, National Health Research Institute, Miaoli 35053, Taiwan
| | - Shih-Fang Huang
- Facility Utilization Group, Experimental Facility Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Yuan-Ling Hsu
- Graduate Institute of Medical Genomics and Proteomics, College of Medicine, National Taiwan University, Taipei 10617, Taiwan
| | - Szu-Hua Pan
- Graduate Institute of Medical Genomics and Proteomics, College of Medicine, National Taiwan University, Taipei 10617, Taiwan
| | - Yen-Ju Chen
- Life science group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Yi-Hung Lin
- Life science group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
- Facility Utilization Group, Experimental Facility Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
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134
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Yang ZH, Zhuo Y, Yuan R, Chai YQ. Amplified thrombin aptasensor based on alkaline phosphatase and hemin/G-quadruplex-catalyzed oxidation of 1-naphthol. ACS Appl Mater Interfaces 2015; 7:10308-10315. [PMID: 25907268 DOI: 10.1021/acsami.5b00988] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An alkaline phosphatase (ALP)-based biosensor can in situ generate an electroactive product by enzymatic hydrolysis of inactive substrates. To obtain a higher signal-to-background ratio, a chemical redox cycling signal-amplified strategy based on the addition of a strong reducing agent has often be applied in the construction of ALP-based biosensors. However, the strong reducing agent not only affects the activity of ALP but also readily reacts with dissolved oxygen, leading to inaccurate results. In this work, a new signal-amplified strategy for a thrombin (TB) aptasensor based on the catalytic oxidation of ALP-generated products, 1-naphthol (NP), using hemin/G-quadruplex DNAzymes was reported. We implemented gold-nanoparticle-decorated zinc oxide nanoflowers (Au-ZnO) as the matrix for immobilizing ALP and TB aptamer (TBA) and then labeled it with hemin to form hemin/G-quadruplex/ALP/Au-ZnO bioconjugates (TBA II bioconjugates). Through a "sandwich" reaction, TBA II bioconjugates were captured on the electrode surface. The amplified signal was carried out in two steps: (i) an ALP-catalyzed inactive substrate, 1-naphthyl phosphate (NPP), in situ produces NP on the surface of the electrode; (ii) on the one hand, NP as a new reactant could be directly electrooxidized and generated an electrochemical signal, but, on the other hand, NP could be oxidized by hemin/G-quadruplex in the presence of H2O2, resulting in amplification of the electrochemical signal. The proposed TB aptasensor achieved a linear range of 1 pM to 30 nM with a detection limit of 0.37 pM (defined as S/N = 3).
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Affiliation(s)
- Zhe-Han Yang
- Key Laboratory of Luminescent and Real-Time Analytical Chemistry and Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
| | - Ying Zhuo
- Key Laboratory of Luminescent and Real-Time Analytical Chemistry and Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
| | - Ruo Yuan
- Key Laboratory of Luminescent and Real-Time Analytical Chemistry and Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
| | - Ya-Qin Chai
- Key Laboratory of Luminescent and Real-Time Analytical Chemistry and Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, P. R. China
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135
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Mao Y, Liu J, He D, He X, Wang K, Shi H, Wen L. Aptamer/target binding-induced triple helix forming for signal-on electrochemical biosensing. Talanta 2015; 143:381-387. [PMID: 26078174 DOI: 10.1016/j.talanta.2015.05.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/28/2015] [Accepted: 05/04/2015] [Indexed: 12/27/2022]
Abstract
Owing to its diversified structures, high affinity, and specificity for binding a wide range of non-nucleic acid targets, aptamer is a useful molecular recognition tool for the design of various biosensors. Herein, we report a new signal-on electrochemical biosensing platform which is based on an aptamer/target binding-induced strand displacement and triple-helix forming. The biosensing platform is composed of a signal transduction probe (STP) modified with a methylene blue (MB) and a sulfhydryl group, a triplex-forming oligonucleotides probe (TFO) and a target specific aptamer probe (Apt). Through hybridization with the TFO probe and the Apt probe, the self-assembled STP on Au electrode via Au-S bonding keeps its rigid structure. The MB on the STP is distal to the Au electrode surface. It is eT off state. Target binding releases the Apt probe and liberates the end of the MB tagged STP to fold back and form a triplex-helix structure with TFO (STP/TFO/STP), allowing MB to approach the Au electrode surface and generating measurable electrochemical signals (eT ON). As test for the feasibility and universality of this signal-on electrochemical biosensing platform, two aptamers which bind to adenosine triphosphate (ATP) and human α-thrombin (Tmb), respectively, are selected as models. The detection limit of ATP was 7.2 nM, whereas the detection limit of Tmb was 0.86 nM.
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Affiliation(s)
- Yinfei Mao
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, PR China
| | - Jinquan Liu
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, PR China
| | - Dinggen He
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, PR China
| | - Xiaoxiao He
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, PR China.
| | - Kemin Wang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, PR China.
| | - Hui Shi
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, PR China
| | - Li Wen
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory for Bio-Nanotechnology and Molecular Engineering of Hunan Province, Hunan University, Changsha 410082, PR China
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136
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Milioli M, Ibáñez-Vea M, Sidoli S, Palmisano G, Careri M, Larsen MR. Quantitative proteomics analysis of platelet-derived microparticles reveals distinct protein signatures when stimulated by different physiological agonists. J Proteomics 2015; 121:56-66. [PMID: 25835965 DOI: 10.1016/j.jprot.2015.03.013] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/13/2015] [Accepted: 03/15/2015] [Indexed: 12/23/2022]
Abstract
UNLABELLED Platelet-derived MPs (PMPs) are a heterogeneous population of microvesicles released from platelets upon activation and apoptosis. Different platelet activations may affect PMP protein profiles and roles in intercellular communication. Here, we performed a quantitative proteomics study to characterize the protein content of PMPs generated by four differentially activated platelet samples. We selected known physiological agonists for platelet activation such as ADP, thrombin and collagen. Thrombin, which is mostly used to generate PMPs in vitro, was set as control. Platelets were activated by following a known agonist strength scale in which ADP was the weakest activation and thrombin and collagen stimulations were the strongest ones. Our proteomic analysis allowed the quantification of 3383 proteins, of which 428 membrane and 131 soluble proteins were found as significantly different in at least one of the analyzed conditions. Activation with stronger agonists led to the enrichment of proteins related to platelet activation in PMPs. In addition, proteins involved in platelet degranulation and proteins from the electron transport chain were less abundant in PMPs when stronger activation was used. Collectively, our data describe the most detailed characterization of PMPs after platelet physiological activation. Furthermore, we show that PMP protein content is highly dependent on the type of physiological agonist involved in platelet stimulation. BIOLOGICAL SIGNIFICANCE Platelet-derived MPs (PMPs) are a population of vesicles generated upon platelet activation by various stimuli known to be involved in several physiological and pathological processes. This manuscript investigates the protein profile of PMPs obtained by performing four different activation protocols using mass spectrometry-based quantitative proteomics. By following a known physiological agonist strength scale our findings suggest a biological link between agonist strength and proteins associated to platelet mediated processes such as activation and degranulation. These data may provide new insights for understanding PMP biological role and formation.
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Affiliation(s)
- Marco Milioli
- Department of Chemistry, University of Parma, 43124 Parma, Italy
| | - Maria Ibáñez-Vea
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Simone Sidoli
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Giuseppe Palmisano
- Institute of Biomedical Sciences, Department of Parasitology, USP, São Paulo, Brazil
| | - Maria Careri
- Department of Chemistry, University of Parma, 43124 Parma, Italy
| | - Martin R Larsen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense M, Denmark.
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137
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Wu M, Algar WR. Acceleration of proteolytic activity associated with selection of thiol ligand coatings on quantum dots. ACS Appl Mater Interfaces 2015; 7:2535-2545. [PMID: 25607728 DOI: 10.1021/am507466b] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Nanoparticle bioconjugates are attractive probes for measuring the activity of hydrolytic enzymes. In these configurations, the localization of multiple copies of a hydrolase substrate to a nanoparticle scaffold has been reported to enhance apparent activity by factors of 2 to 3 compared to that for equivalent amounts of substrate in bulk solution. Here, we studied the effect of surface chemistry on protease activity using multivalent QD-peptide substrate conjugates as a model system. QDs were coated with cysteine (CYS), glutathione (GSH), dihydrolipoic acid (DHLA), or 3-mercaptopropionic acid (MPA) ligands, and thrombin and trypsin were used as model proteases. Proteolytic activity was measured for different combinations of ligand and protease using Förster resonance energy transfer (FRET)-based assays. The highest levels of activity were observed with CYS and GSH coatings, and the lowest levels of activity were observed with DHLA and MPA coatings. In all cases, proteolytic activity was accelerated compared to that for an equivalent amount of substrate in bulk solution, with up to 80- and 65-fold increases in the apparent specificity constants for thrombin and trypsin, respectively. Thrombin was more strongly affected by the QD surface chemistry, with up to a 50-fold variation in its apparent specificity constant between ligand coatings, whereas only a 5-fold variation was observed with trypsin. These trends were correlated to adsorption of the proteases on the QDs and are discussed in the context of the physicochemical properties of both components. This work clearly indicates a critical role for the nanoparticle interface in mediating substrate turnover and provides some of the strongest support to date for a so-called hopping model of activity.
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Affiliation(s)
- Miao Wu
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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138
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Tripodi A, Chantarangkul V, Santagostino E. Failure of corn trypsin inhibitor to affect the thrombin generation assay in plasma from severe haemophiliacs: comment. J Thromb Haemost 2015; 13:163-4. [PMID: 25354335 DOI: 10.1111/jth.12769] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 10/17/2014] [Indexed: 11/27/2022]
Affiliation(s)
- A Tripodi
- Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Department of Clinical Sciences and Community Health, Università degli Studi di Milano and IRCCS Maggiore Hospital Foundation, Milan, Italy
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139
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Abstract
Liver disease results in complex alterations of all 3 phases of hemostasis. It is now recognized that hemostasis is rebalanced in chronic liver disease. The fall in clotting factor levels is accompanied by a parallel fall in anticoagulant proteins. High von Willebrand factor levels counteract defects in primary hemostasis. Conventional coagulation tests do not fully reflect the derangement in hemostasis and do not accurately predict the risk of bleeding. Global coagulation assays (thrombin generation, thromboelastography) reflect the interaction between procoagulant factors, anticoagulant factors, platelets, and the fibrinolytic system and show promise for assessing bleeding risk and guiding therapy. These assays are not yet commercially approved or validated. Prevention of bleeding should not be aimed at correcting conventional coagulation tests. Thrombopoietin receptor agonists were shown to increase the platelet count in cirrhotic patients undergoing invasive procedures but may increase the risk of thrombosis. Rebalanced hemostasis in liver disease is precarious and may be tipped toward hemorrhage or thrombosis depending on coexisting circumstantial risk factors. Bacterial infection may impair hemostasis in cirrhosis by triggering the release of endogenous heparinoids. There are no evidence-based guidelines for hemostatic therapy of acute hemorrhage in liver disease. There is currently inadequate evidence to support the use of recombinant FVIIa, prothrombin complex concentrates, or tranexamic acid in acute variceal or other hemorrhage.
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Affiliation(s)
- Jody L Kujovich
- Oregon Health & Science University, Pediatric Hematology/Oncology, Oregon Hemophilia Center, Portland, OR
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140
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Van Meervelt V, Soskine M, Maglia G. Detection of two isomeric binding configurations in a protein-aptamer complex with a biological nanopore. ACS Nano 2014; 8:12826-35. [PMID: 25493908 PMCID: PMC4410316 DOI: 10.1021/nn506077e] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Protein-DNA interactions play critical roles in biological systems, and they often involve complex mechanisms and dynamics that are not easily measured by ensemble experiments. Recently, we showed that folded proteins can be internalized inside ClyA nanopores and studied by ionic current recordings at the single-molecule level. Here, we use ClyA nanopores to sample the interaction between the G-quadruplex fold of the thrombin binding aptamer (TBA) and human thrombin (HT). Surprisingly, the internalization of the HT:TBA complex inside the nanopore induced two types of current blockades with distinguished residual current and lifetime. Using single nucleobase substitutions to TBA we showed that these two types of blockades originate from TBA binding to thrombin with two isomeric orientations. Voltage dependencies and the use of ClyA nanopores with two different diameters allowed assessing the effect of the applied potential and confinement and revealed that the two binding configurations of TBA to HT display different lifetimes. These results show that the ClyA nanopores can be used to probe conformational heterogeneity in protein:DNA interactions.
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Affiliation(s)
| | - Misha Soskine
- Department of Chemistry, KU Leuven, Leuven, B-3001, Belgium
| | - Giovanni Maglia
- Department of Chemistry, KU Leuven, Leuven, B-3001, Belgium
- Groningen Biomolecular Science and Biotechnology Institute, University of Groningen, the Netherlands
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141
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Tseng WL, Chen TH, Huang CC, Huang YH, Yeh CF, Tsai HJ, Lee HY, Kao CY, Lin SW, Liao HR, Cheng JC, Tseng CP. Impaired thrombin generation in Reelin-deficient mice: a potential role of plasma Reelin in hemostasis. J Thromb Haemost 2014; 12:2054-64. [PMID: 25255925 DOI: 10.1111/jth.12736] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 08/25/2014] [Indexed: 01/06/2023]
Abstract
BACKGROUND Reelin is a large extracellular glycoprotein that is present in the peripheral blood. That Reelin interacts with the coagulation components and elicits a functional role in hemostasis has not yet been elucidated. OBJECTIVES The hemostatic activity of Reelin is investigated and defined in this study. METHODS The interplay of Reelin with coagulation components was elucidated by far-Western and liposome/platelet binding assays. In vivo and ex vivo hemostasis-related analyses of Reelin-deficient mice and plasma were also performed. RESULTS Reelin interacted with the liposomes containing phosphatidylserine (PS) or phosphatidylcholine. Instead of interacting with known Reelin receptors (ApoE receptor 2, very low density lipoprotein receptor and integrin β1), Reelin interacted with PS of the activated platelets. The interaction between Reelin and the coagulation factors of thrombin and FXa was also demonstrated with the Kd of 11.7 and 21.2 nm, respectively. Reelin-deficient mice displayed a prolonged bleeding time and an increase in rebleeding rate. Despite the fact that Reelin deficiency had no significant effect on the clotting time of prothrombin and activated partial thromboplastin time, the fibrin clot formation was abnormal and the fibrin clot structure was relatively loosened with reduced clot strength. Abnormal fibrinogen expression did not account for the hemostatic defects associated with Reelin deficiency. Instead, thrombin generation was impaired concomitant with an altered prothrombin cleavage pattern. CONCLUSIONS By interacting with platelet phospholipids and the coagulation factors, thrombin and FXa, Reelin plays a selective role in coagulation activation, leading to thrombin generation and formation of a normal fibrin clot.
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Affiliation(s)
- W-L Tseng
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Kweishan, Taoyuan, Taiwan
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142
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Gangadharan B, Delignat S, Ollivier V, Gupta N, Mackman N, Kaveri SV, Lacroix-Desmazes S. Role of coagulation-associated processes on factor VIII immunogenicity in a mouse model of severe hemophilia A. J Thromb Haemost 2014; 12:2065-9. [PMID: 25267332 DOI: 10.1111/jth.12740] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 09/15/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND Immune responses to therapeutic factor VIII remain a major problem, affecting 30% of patients with severe hemophilia A. The primary factors that drive immune responses in these patients remain elusive. There have been conflicting reports on a role of coagulation (or thrombin) in anti-FVIII immune responses. OBJECTIVE To assess the importance of coagulation-associated processes for the onset of the anti-FVIII immune response. METHODS Using FVIII-deficient mice, we compared the immunogenicity of recombinant FVIII or the inactive FVIII(V) (634M) mutant. In parallel, the involvement of tissue factor (TF) activity in the anti-FVIII immune response was investigated upon injection of a neutralizing anti-TF antibody or by the use of chimeric mice that lack TF expression in myeloid cells. The development of the anti-FVIII immune response was also monitored after treatment with warfarin. RESULTS The kinetics of the development of antibody responses to FVIII(V) (634M) were indistinguishable from those of wild-type FVIII. Inhibition of TF activity did not modulate immune responses to exogenous FVIII. Additionally, global inhibition of coagulation with warfarin failed to reduce the anti-FVIII immune response. CONCLUSIONS Thrombin generation or coagulation-associated processes do not modulate the anti-FVIII antibody response in mouse model of severe hemophilia A.
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Affiliation(s)
- B Gangadharan
- Centre de Recherche des Cordeliers, Institut National de la Santé et de la Recherche Médicale (INSERM), Unité Mixte de Recherche en Santé (UMR S) 1138, Paris, France; Centre de Recherche des Cordeliers, UMR S 1138, Université Pierre et Marie Curie-Paris 6, Paris, France; Centre de Recherche des Cordeliers, Université Paris Descartes, UMR S 1138, Paris, France
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Alamelu J, Bevan D, Sorensen B, Rangarajan S. Pharmacokinetic and pharmacodynamic properties of plasma-derived vs. recombinant factor IX in patients with hemophilia B: a prospective crossover study. J Thromb Haemost 2014; 12:2044-8. [PMID: 25315324 DOI: 10.1111/jth.12756] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 10/12/2014] [Indexed: 08/31/2023]
Abstract
BACKGROUND Effective treatment of acute bleeding episodes in patients with hemophilia B relies on factor IX recovery, with higher levels being more desirable, whereas prevention of bleeds with a prophylactic regimen depends on the half-life of the product. Lower recovery values have been reported following administration of recombinant FIX (rFIX) than following administration of plasma-derived FIX (pdFIX). OBJECTIVES To compare the pharmacokinetic and pharmacodynamic properties of rFIX and pdFIX in patients with hemophilia B. METHODS A prospective crossover study of nine patients with moderate to severe hemophilia B was performed. Following a washout period, 50 U kg(-1) FIX was administered, and blood samples were taken as per protocol up to 48 h postinfusion. Paired data were analyzed with the Wilcoxon signed rank test. RESULTS Mean peak recovery at 10 min postinfusion was 62.14 IU dL(-1) with pdFIX and 52.7 IU dL(-1) with rFIX (P = 0.08). Mean half-life was 16.6 h with pdFIX and 17.5 h with rFIX (P = 0.55). Maximum peak thrombin generation (PTG) was 35.9 nm with pdFIX and 28.9 nm with rFIX (P = 0.21). Administration of rFIX resulted in early PTG, whereas administration of pdFIX resulted in slightly later and sustained PTG. At 48 h, PTG was similar with pdFIX (19.0 nm) and rFIX (19.4 nm) (P = 0.91). CONCLUSIONS Patients experienced better recovery with pdFIX than with rFIX. pdFIX and rFIX had similar half-lives. Maximum PTG was higher for pdFIX; however, this difference did not reach statistical significance. The clinical impact of the slightly increased, delayed and sustained PTG with pdFIX requires further investigation.
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Affiliation(s)
- J Alamelu
- Centre for Haemostasis and Thrombosis, Guy's and St Thomas' NHS Foundation Trust, London, UK
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144
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Abstract
The treatment of many diseases such as cancer requires the use of drugs that can cause severe side effects. Off-target toxicity can often be reduced simply by directing the drugs specifically to sites of diseases. Amidst increasingly sophisticated methods of targeted drug delivery, we observed that Nature has already evolved elegant means of sending biological molecules to where they are needed. One such example is corticosteroid binding globulin (CBG), the major carrier of the anti-inflammatory hormone, cortisol. Targeted release of cortisol is triggered by cleavage of CBG's reactive centre loop by elastase, a protease released by neutrophils in inflamed tissues. This work aimed to establish the feasibility of exploiting this mechanism to carry therapeutic agents to defined locations. The reactive centre loop of CBG was altered with site-directed mutagenesis to favour cleavage by other proteases, to alter the sites at which it would release its cargo. Mutagenesis succeeded in making CBG a substrate for either prostate specific antigen (PSA), a prostate-specific serine protease, or thrombin, a key protease in the blood coagulation cascade. PSA is conspicuously overproduced in prostatic hyperplasia and is, therefore, a good way of targeting hyperplastic prostate tissues. Thrombin is released during clotting and consequently is ideal for conferring specificity to thrombotic sites. Using fluorescence-based titration assays, we also showed that CBG can be engineered to bind a new compound, thyroxine-6-carboxyfluorescein, instead of its physiological ligand, cortisol, thereby demonstrating that it is possible to tailor the hormone binding site to deliver a therapeutic drug. In addition, we proved that the efficiency with which CBG releases bound ligand can be increased by introducing some well-placed mutations. This proof-of-concept study has raised the prospect of a novel means of targeted drug delivery, using the serpin conformational change to combat the problem of off-target effects in the treatment of diseases.
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Affiliation(s)
- Wee Lee Chan
- Department of Haematology, University of Cambridge, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Aiwu Zhou
- Key Laboratory of Cell Differentiation and Apoptosis of Ministry of Education of China, Shanghai Jiao Tong University, School of Medicine, Shanghai, People's Republic of China
| | - Randy J. Read
- Department of Haematology, University of Cambridge, Cambridge Institute for Medical Research, Addenbrooke's Hospital, Cambridge, United Kingdom
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145
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Abstract
Atomic force microscopy-based adhesion force measurements have emerged as a powerful tool for the biophysical analyses of biological systems. Such measurements can now be extended to detection and mapping of biomolecules on surfaces via integrated imaging and force spectroscopy techniques. Critical to these experiments is the choice of the biomolecular recognition probe. In this study, we demonstrate how oligonucleotide aptamers can be used as versatile probes to simultaneously image and spatially locate targets on surfaces. We focus on two structurally distinct proteins relevant to the clotting cascade - human α-thrombin and vascular endothelial growth factor. Via AFM-recognition mapping using specific DNA aptamers on a commercially available instrument, we show a clear consistency between height and force measurements obtained simultaneously. Importantly, we are able to observe changes in binding due to changes in the external microenvironment, which demonstrate the ability to study fluctuating biological systems in real time. The aptamer specificity and the ability to distinguish their targets are shown through positive and negative controls. It is therefore possible to generate high resolution maps to spatially and temporally identify proteins at the molecular level on complex surfaces.
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146
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Henry BL, Desai UR. Sulfated low molecular weight lignins, allosteric inhibitors of coagulation proteinases via the heparin binding site, significantly alter the active site of thrombin and factor xa compared to heparin. Thromb Res 2014; 134:1123-9. [PMID: 25242245 PMCID: PMC4253681 DOI: 10.1016/j.thromres.2014.08.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/19/2014] [Accepted: 08/23/2014] [Indexed: 10/24/2022]
Abstract
Sulfated low molecular weight lignins (LMWLs) have been found to bind in the heparin binding sites of coagulation proteinases. LMWLs represent a library of diverse non-carbohydrate, aromatic molecules which are structures different from heparin, but still potently inhibit thrombin and factor Xa. To better understand their mechanism of action, we studied the effects of three sulfated LMWLs (CDSO3, FDSO3, and SDSO3) on the active sites of thrombin and factor Xa. LMWLs were found to uniformly inhibit the catalytic activity of thrombin and factor Xa, regardless of the substrate used. Michaelis-Menten kinetic studies indicate that maximal velocity of hydrolysis of each chromogenic substrate decreases significantly in the presence of sulfated LMWLs, while the effect on Michaelis constant is dependent on the nature of the substrate. These studies indicate that LMWLs inhibit thrombin and factor Xa through allosteric disruption of the catalytic apparatus, specifically through the catalytic step. As opposed to heparin, LMWLs significantly alter the binding of the active site fluorescent ligand p-aminobenzamidine. LMWLs also had a greater effect on the molecular orientation of fluorescein-labeled His 57 than heparin. The molecular geometry surrounding the most important catalytic amino acid, Ser 195, was significantly altered by the binding of LMWLs while heparin had no measurable effect on Ser 195. These results further advance the concept of sulfated LMWLs as heparin mimics and will aid the design of anticoagulants based on their novel scaffold.
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Affiliation(s)
- Brian L Henry
- Department of Cardiology, Heart and Vascular Institute, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
| | - Umesh R Desai
- Department of Medicinal Chemistry, Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, Virginia
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147
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Hansson KM, Nielsen S, Elg M, Deinum J. The effect of corn trypsin inhibitor and inhibiting antibodies for FXIa and FXIIa on coagulation of plasma and whole blood. J Thromb Haemost 2014; 12:1678-86. [PMID: 25142753 DOI: 10.1111/jth.12707] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 08/10/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND Corn trypsin inhibitor (CTI), an inhibitor of FXIIa, is used to prevent plasma coagulation by contact activation, to specifically investigate tissue factor (TF)-initiated coagulation. OBJECTIVE In the present work the specificity of CTI for factor (F) XIIa is questioned. METHODS AND RESULTS In the commercial available plasma coagulation assays CTI was found to double activated partial thromboplastin time (APTT) at a plasma concentration of 7.3 ± 1.5 μm CTI (assay concentration 2.4 μm). No effect was found on the prothrombin time (PT) when high TF concentrations were used. Also, with specific antibodies for FXIIa and for FXIa only APTT was found to be extended but not PT. With specific enzyme assays using chromogenic substrates CTI was shown to be a strong inhibitor of FXIIa and a competitive inhibitor of FXIa with Ki = 8.1 ± 0.3 μm, without effect on the coagulation factors FVIIa, FIXa, FXa and thrombin. In thrombin generation and coagulation (free oscillation rheometry, FOR) assays, initiated with low TF concentrations, no effect of CTI (plasma concentrations of 4.4 and 13.6 μm CTI, 25 resp. 100 mg L(-1) in blood) was found with ≥ 1 pm TF. At ≤ 0.1 pm TF in the FOR whole blood assay the coagulation time (CT) concentration dependently increased while the plasma CT became longer than the observation time. CONCLUSION To avoid inhibition of FXIa and the thrombin feedback loop we recommend that for coagulation assays the concentration of CTI in blood should be below 20 mg L(-1) (1.6 μm) and in plasma below 3 μm.
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Affiliation(s)
- K M Hansson
- CVMD iMED, AstraZeneca R&D Mölndal, Mölndal, Sweden
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148
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Kleinegris MC, Bos MHA, Roest M, Henskens Y, Ten Cate-Hoek A, Van Deursen C, Spronk HMH, Reitsma PH, De Groot PG, Ten Cate H, Koek G. Cirrhosis patients have a coagulopathy that is associated with decreased clot formation capacity. J Thromb Haemost 2014; 12:1647-57. [PMID: 25142532 DOI: 10.1111/jth.12706] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 07/24/2014] [Indexed: 12/20/2022]
Abstract
BACKGROUND The coagulopathy in cirrhosis is associated with thrombosis and bleeding. OBJECTIVES To gain better insights into the coagulopathy in patients with cirrhosis, we evaluated plasma thrombin generation and whole blood clot formation in a cross-sectional study. METHODS Blood was collected from 73 patients with all-cause cirrhosis (Child-Pugh-A n = 52, B n = 15, C n = 6) and 20 healthy controls. Activity of the coagulation pathways was measured with assays for factor (F) VIIa and FIXa-antithrombin and FXa-antithrombin complexes, respectively. Thrombin generation by calibrated automated thrombography was determined in platelet-poor plasma using a 1 or 5 pm tissue factor trigger with/without thrombomodulin. ROTEM measurements were performed in whole blood triggered with 35 pm tissue factor without/with 175 ng mL(-1) tissue plasminogen activator (the latter refered to as 'tPA-ROTEM'). RESULTS We observed an increased generation of FVIIa and a moderately elevated amount of FIXa (in complex with antithrombin) without apparent increase in FX activation in patients with cirrhosis. In accordance with this prothrombotic state, markers of thrombin generation potential were also increased upon increasing severity of cirrhosis. In the whole blood clotting assay we observed delayed clot formation and decreased clot strength associated with increased severity of cirrhosis. No significant differences were found for tPA-ROTEM parameters of clot degradation. CONCLUSION These results indicate that cirrhosis patients have an overall procoagulant plasma milieu but a decreased whole blood clot formation capacity with an apparently unaltered resistance to clot lysis.
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Affiliation(s)
- M-C Kleinegris
- Laboratory for Clinical Thrombosis and Hemostasis, Department of Internal Medicine, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands
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149
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Plug T, Kramer G, Meijers JCM. A role for arginine-12 in thrombin-thrombomodulin-mediated activation of thrombin-activatable fibrinolysis inhibitor. J Thromb Haemost 2014; 12:1717-25. [PMID: 25066897 DOI: 10.1111/jth.12674] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 07/14/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND Thrombin-activatable fibrinolysis inhibitor (TAFI) is a proenzyme that links coagulation and fibrinolysis. TAFI can be activated by thrombin, the thrombin-thrombomodulin complex and plasmin through cleavage of the first 92 amino acids from the enzyme. In silico analysis of the TAFI sequence revealed a potential thrombin cleavage site at Arg12. The aim of this study was to determine whether TAFI can be cleaved at Arg12 and whether this cleavage plays a role in TAFI activation. METHODS A peptide based on the first 18 amino acids of TAFI was used to determine whether thrombin was able to cleave at Arg12. Mass spectrometry was performed to determine whether the Arg12-cleaved peptide was released from full-length TAFI. Furthermore, a TAFI mutant in which Arg12 was replaced by a glutamine (TAFI-R12Q) was constructed and characterized with respect to its activation kinetics. RESULTS The peptide and mass spectrometry data showed that thrombin was able to cleave TAFI at Arg12, but with low efficiency in full-length TAFI. Characterization of TAFI-R12Q showed no difference in thrombin-mediated activation from wild-type TAFI. However, there was an approximately 60-fold impairment in activation of TAFI-R12Q by the thrombin-thrombomodulin complex. CONCLUSIONS Arg12 of TAFI plays an important role in thrombomodulin-mediated TAFI activation by thrombin. Thrombin is able to cleave TAFI at Arg12, but it remains to be determined whether Arg12 is part of an exosite for thrombomodulin or whether cleavage at Arg12 accelerates thrombomodulin-mediated TAFI activation.
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Affiliation(s)
- T Plug
- Department of Experimental Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands
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150
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Shangguan L, Zhu W, Xue Y, Liu S. Construction of photoelectrochemical thrombin aptasensor via assembling multilayer of graphene-CdS nanocomposites. Biosens Bioelectron 2014; 64:611-7. [PMID: 25314620 DOI: 10.1016/j.bios.2014.09.072] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 09/25/2014] [Accepted: 09/25/2014] [Indexed: 12/30/2022]
Abstract
A photoelectrochemical (PEC) aptasensor for highly sensitive and specific detection of thrombin was developed by using graphene–CdS nanocomposites multilayer as photoactive species and electroactive mediator hexaammineruthenium(III) chloride (Ru(NH(3))(6)(3+)) as signal enhancer. Graphene–CdS nanocomposites (G–CdS) were synthesized by one-pot reduction of oxide graphene and CdCl2 with thioacetamide. The photoactive multilayer was prepared by alternative assembly of the negatively charged 3-mercaptopropionic acid modified graphene–CdS nanocomposites (MPA-G–CdS) and the positively charged polyethylenimine (PEI) on ITO electrode. This layer-by-layer assembly method enhanced the stability and homogeneity of the photocurrent readout of G–CdS. Thrombin aptamer was covalently bound to the multilayer by using glutaraldehyde as cross-linking. Electroactive mediator (Ru(NH(3))(6)(3+)) could interact with the DNA phosphate backbone and thus facilitated the electron transfer between G–CdS multilayer and electrode and enhanced the photocurrent. Hybridizing of a long complementary DNA with thrombin aptamer could increase the adsorption amount of (Ru(NH(3))(6)(3+)), which in turn boosted the signal readout. In the presence of target thrombin, the affinity interaction between thrombin and its aptamer resulted in the long complementary DNA releasing from the G–CdS multilayer and decreasing of photocurrent signal. On the basis of G–CdS multilayer as the photoactive species, (Ru (NH(3))(6)(3+)) as an electroactive mediator, and aptamer as a recognition module, a high sensitive PEC aptasensor for thrombin detection was proposed. The thrombin aptasensor displayed a linear range from 2.0 pM to 600.0 pM and a detection limit of 1.0 pM. The present strategy provided a promising ideology for the future development of PEC biosensor.
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Affiliation(s)
- Li Shangguan
- Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, PR China
| | - Wei Zhu
- Jingjiang People's Hospital, PR China
| | | | - Songqin Liu
- Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, PR China; Suzhou Research Institute of Southeast University, PR China.
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