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Jhun CS, Xu L, Siedlecki C, Bartoli CR, Yeager E, Lukic B, Scheib CM, Newswanger R, Cysyk JP, Shen C, Bohnenberger K, Weiss WJ, Rosenberg G. Kinetic and Dynamic Effects on Degradation of von Willebrand Factor. ASAIO J 2023; 69:467-474. [PMID: 36399789 PMCID: PMC10143388 DOI: 10.1097/mat.0000000000001848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The loss of high molecular weight multimers (HMWM) of von Willebrand factor (vWF) in aortic stenosis (AS) and continuous-flow left ventricular assist devices (cf-LVADs) is believed to be associated with high turbulent blood shear. The objective of this study is to understand the degradation mechanism of HMWM in terms of exposure time (kinetic) and flow regime (dynamics) within clinically relevant pathophysiologic conditions. A custom high-shear rotary device capable of creating fully controlled exposure times and flows was used. The system was set so that human platelet-poor plasma flowed through at 1.75 ml/sec, 0.76 ml/sec, or 0.38 ml/sec resulting in the exposure time ( texp ) of 22, 50, or 100 ms, respectively. The flow was characterized by the Reynolds number (Re). The device was run under laminar (Re = 1,500), transitional (Re = 3,000; Re = 3,500), and turbulent (Re = 4,500) conditions at a given texp followed by multimer analysis. No degradation was observed at laminar flow at all given texp . Degradation of HMWM at a given texp increases with the Re. Re ( p < 0.0001) and texp ( p = 0.0034) are significant factors in the degradation of HMWM. Interaction between Re and texp , however, is not always significant ( p = 0.73).
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Affiliation(s)
- Choon-Sik Jhun
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Lichong Xu
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Christopher Siedlecki
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
- Department of Biomedical Engineering, College of Engineering, The Pennsylvania State University, University Park, Pennsylvania
| | - Carlo R. Bartoli
- Department of Cardiothoracic Surgery, Geisinger Medical Center, Danville, Pennsylvania
| | - Eric Yeager
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Branka Lukic
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Christopher M. Scheib
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Raymond Newswanger
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Joshua P. Cysyk
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Chan Shen
- Division of Outcomes Research and Quality, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Karl Bohnenberger
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - William J. Weiss
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
- Department of Biomedical Engineering, College of Engineering, The Pennsylvania State University, University Park, Pennsylvania
| | - Gerson Rosenberg
- From the Division of Applied Biomedical Engineering, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
- Department of Biomedical Engineering, College of Engineering, The Pennsylvania State University, University Park, Pennsylvania
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Pillai VG, Zheng XL. A novel mechanism underlying allosteric regulation of ADAMTS-13 revealed by hydrogen-deuterium exchange plus mass spectrometry. Res Pract Thromb Haemost 2022; 7:100012. [PMID: 36852110 PMCID: PMC9958085 DOI: 10.1016/j.rpth.2022.100012] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/11/2022] [Accepted: 11/14/2022] [Indexed: 02/15/2023] Open
Abstract
Background ADAMTS-13, a plasma metalloprotease, cleaves von Willebrand factor. ADAMTS-13 activity appears to be regulated through allosteric inhibition by its distal C-terminus. Objectives The objective of this study was to better understand how domain-domain interactions may affect ADAMTS-13 conformations and functions. Methods We performed deuterium-hydrogen exchange plus mass spectrometry to assess the number and rate of deuterium incorporation into various peptides of full-length ADAMTS-13 and its truncated variants. Results Under physiological conditions, a bimodal distribution of deuterium incorporation was detected in the peptides from metalloprotease (217-230 and 282-304), cysteine-rich (446-482), and CUB (for complement C1r/C1s, Uegf, Bmp1) domains (1185-1214, 1313-1330, 1341-1347, 1358-1378, and 1393-1407) of full-length recombinant ADAMTS-13, but not of truncated variants. These results suggest that the full-length ADAMTS-13 undergoes conformational changes. On removal of the middle and distal C-terminal domains, the number and rate of deuterium incorporation were increased in the peptides from cysteine-rich (445-467, 467-482, and 495-503) and spacer domains (621-642 and 655-654) but decreased in the peptides from metalloprotease (115-124, 217-230, and 274-281). Moreover, most peptides, except for 217-230 and 1357-1376, exhibited a pD-dependent deuterium incorporation in the full-length ADAMTS-13, but not in the truncated variant (eg, MDTCS or T5C). These results further suggest that the bimodal deuterium incorporation observed in the peptides from the full-length ADAMTS-13 is the result of potential impact from the middle to distal C-terminal domains. Surface plasmon resonance revealed the direct binding interactions between the distal and proximal domains of ADAMTS-13. Conclusion Our results provide novel insight on how intramolecular interactions may affect conformations of ADAMTS-13, thus regulating its proteolytic functions.
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Affiliation(s)
- Vikram G. Pillai
- Department of Pathology and Laboratory Medicine, The University of Kansas Medical Center, Kansas City, USA,Department of Biophysics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - X. Long Zheng
- Department of Pathology and Laboratory Medicine, The University of Kansas Medical Center, Kansas City, USA,Institute of Reproductive Medicine and Developmental Sciences, The University of Kansas Medical Center, Kansas City, USA,Correspondence X. Long Zheng, MD, PhD, Department of Pathology and Laboratory Medicine, The University of Kansas Medical Center, 3901 Rainbow Boulevard, 5016 Delp, Kansas City, Kansas 66160, USA.
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Rossato P, Glantschnig H, Leidenmühler P, Kopic A, Ruthsatz T, Majer B, Schuster M, Scheiflinger F, Höllriegl W. Absence of exaggerated pharmacology by recombinant ADAMTS13 in the rat and monkey. Blood Coagul Fibrinolysis 2022; 33:56-60. [PMID: 34267062 PMCID: PMC8728677 DOI: 10.1097/mbc.0000000000001064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 06/25/2021] [Accepted: 07/05/2021] [Indexed: 12/02/2022]
Abstract
Insufficiency of ADAMTS13 (a disintegrin and metalloprotease with thrombospondin motif repeats-13) is the cause of thrombotic thrombocytopenic purpura (TTP) and contributes in microangiopathy in sickle cell disease (SCD). Recombinant ADAMTS13 effectively cleaves prothrombotic ultra-large von Willebrand factor (VWF) multimers. It is being tested as replacement therapy for TTP, and at supra-physiologic concentrations, for moderating vaso-occlusive crisis in SCD. Deficiencies of VWF, or concomitant treatment with antithrombotic drugs, could pose risks for increased bleeds in these patient populations. The purpose of the experiments was to evaluate the potential of exaggerated pharmacology and temporary bleeding risks associated with rADAMTS13 administration. We utilized safety studies in monkey and tested the effects of administering maximum-feasible doses of rADAMTS13 on nonclinical safety and spontaneous or aggressive bleeds in the rat model. Evaluation of pharmacokinetics, toxicity profiles, and challenge in a tail-tip bleeding model show that treatment with rADAMTS13 did not increase bleeding tendency, either alone, or in combination with enoxaparin or acetylsalicylic-acid. These novel findings demonstrate absence of rADAMTS13 exaggerated pharmacology without spontaneous or aggravated bleeds even at supra-physiologic (>100-fold) plasma concentrations.
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Affiliation(s)
- Paolo Rossato
- Baxalta Innovations GmbH, A Takeda Company, Vienna, Austria
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4
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Buhr CR, Eckrich J, Kluenker M, Bruns K, Wiesmann N, Tremel W, Brieger J. Determination of the LD 50 with the chick embryo chorioallantoic membrane (CAM) assay as a promising alternative in nanotoxicological evaluation. Nanotoxicology 2021; 15:690-705. [PMID: 33979554 DOI: 10.1080/17435390.2021.1916635] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Toxicity tests in rodents are still considered a controversial topic concerning their ethical justifiability. The chick embryo chorioallantoic membrane (CAM) assay may offer a simple and inexpensive alternative. The CAM assay is easy to perform and has low bureaucratic hurdles. At the same time, the CAM assay allows the application of a broad variety of analytical methods in the field of nanotoxicological research. We evaluated the CAM assay as a methodology for the determination of nanotoxicity. Therefore we calculated the median lethal dose (LD50), performed in vivo microscopy and immunohistochemistry to identify organ-specific accumulation profiles, potential organ damage, and the kinetics of the in vivo circulation of the nanoparticles. Zinc oxide nanoparticles were intravascularly injected on day 10 of the egg development and showed an LD50 of 17.5 µM (1.4 µg/mLeggcontent). In comparison, the LD50 of equivalent amounts of Zn2+ was 4.6 µM (0.6 µg/mLeggcontent). Silica encapsulated ZnO@SiO2 nanoparticles conjugated with fluorescein circulated in the bloodstream for at least 24 h. Particles accumulated mostly in the liver and kidney. In immunohistochemical staining, organ damage was detected only in liver tissue after intravascular injection of zinc oxide nanoparticles in very high concentrations. Zinc oxide nanoparticles showed a different pharmacokinetic profile compared to Zn2+ ions. In conclusion, the CAM assay has proven to be a promising methodology for evaluating nanotoxicity and for the assessment of the in vivo accumulation profiles of nanoparticles. These findings may qualify the methodology for risk assessment of innovative nanotherapeutics in the future.
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Affiliation(s)
- Christoph Raphael Buhr
- Department of Otorhinolaryngology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Jonas Eckrich
- Department of Otorhinolaryngology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Martin Kluenker
- Department of Chemistry, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Kai Bruns
- Department of Clinical Chemistry and Laboratory Medicine, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Nadine Wiesmann
- Department of Otorhinolaryngology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany.,Department of Oral and Maxillofacial Surgery, Plastic Surgery, University Medical Center Mainz, Mainz, Germany
| | - Wolfgang Tremel
- Department of Chemistry, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Jürgen Brieger
- Department of Otorhinolaryngology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
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5
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Del Amo-Maestro L, Sagar A, Pompach P, Goulas T, Scavenius C, Ferrero DS, Castrillo-Briceño M, Taulés M, Enghild JJ, Bernadó P, Gomis-Rüth FX. An Integrative Structural Biology Analysis of Von Willebrand Factor Binding and Processing by ADAMTS-13 in Solution. J Mol Biol 2021; 433:166954. [PMID: 33771572 DOI: 10.1016/j.jmb.2021.166954] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
Von Willebrand Factor (vWF), a 300-kDa plasma protein key to homeostasis, is cleaved at a single site by multi-domain metallopeptidase ADAMTS-13. vWF is the only known substrate of this peptidase, which circulates in a latent form and becomes allosterically activated by substrate binding. Herein, we characterised the complex formed by a competent peptidase construct (AD13-MDTCS) comprising metallopeptidase (M), disintegrin-like (D), thrombospondin (T), cysteine-rich (C), and spacer (S) domains, with a 73-residue functionally relevant vWF-peptide, using nine complementary techniques. Pull-down assays, gel electrophoresis, and surface plasmon resonance revealed tight binding with sub-micromolar affinity. Cross-linking mass spectrometry with four reagents showed that, within the peptidase, domain D approaches M, C, and S. S is positioned close to M and C, and the peptide contacts all domains. Hydrogen/deuterium exchange mass spectrometry revealed strong and weak protection for C/D and M/S, respectively. Structural analysis by multi-angle laser light scattering and small-angle X-ray scattering in solution revealed that the enzyme adopted highly flexible unbound, latent structures and peptide-bound, active structures that differed from the AD13-MDTCS crystal structure. Moreover, the peptide behaved like a self-avoiding random chain. We integrated the results with computational approaches, derived an ensemble of structures that collectively satisfied all experimental restraints, and discussed the functional implications. The interaction conforms to a 'fuzzy complex' that follows a 'dynamic zipper' mechanism involving numerous reversible, weak but additive interactions that result in strong binding and cleavage. Our findings contribute to illuminating the biochemistry of the vWF:ADAMTS-13 axis.
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Affiliation(s)
- Laura Del Amo-Maestro
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain
| | - Amin Sagar
- Centre de Biochimie Structurale, INSERM, CNRS and Université de Montpellier, 34090 Montpellier, France
| | - Petr Pompach
- Institute of Microbiology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 252 50 Vestec, Czechia; Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Prumyslova 595, 252 50 Vestec, Czechia
| | - Theodoros Goulas
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain
| | - Carsten Scavenius
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark
| | - Diego S Ferrero
- Laboratory for Viruses and Large Biological Complexes, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain
| | - Mariana Castrillo-Briceño
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain
| | - Marta Taulés
- Scientific and Technological Centers (CCiTUB), University of Barcelona, Lluís Solé i Sabaris, 1-3, 08028 Barcelona, Catalonia, Spain
| | - Jan J Enghild
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark
| | - Pau Bernadó
- Centre de Biochimie Structurale, INSERM, CNRS and Université de Montpellier, 34090 Montpellier, France.
| | - F Xavier Gomis-Rüth
- Proteolysis Laboratory, Department of Structural Biology, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park, c/Baldiri Reixac, 15-21, 08028 Barcelona, Catalonia, Spain.
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Browning S, Bahar B, Lee AI, Gorshein E. Spontaneous recovery in a patient with acquired thrombotic thrombocytopenic purpura (TTP): observation of a 'subclinical' TTP state. ACTA ACUST UNITED AC 2021; 25:473-477. [PMID: 33269995 DOI: 10.1080/16078454.2020.1848973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVES Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy that can have high mortality rates without prompt treatment. Standard treatment is urgent plasma exchange (PLEX), which leads to disease remission in the vast majority of patients. Deficiency of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) alone is not sufficient to cause the clinical manifestations characteristic of TTP. We present a case of acquired TTP, where spontaneous recovery was observed prior to initiation of any TTP-specific therapy. CLINICAL PRESENTATION A 73-year-old asymptomatic female presented with new-onset mild haemolytic anaemia and thrombocytopenia. Further testing revealed a significantly reduced ADAMTS13 activity level and an ADAMTS13 inhibitor, concerning for acquired TTP. On reassessment, the patient's haematologic parameters had been corrected prior to initiation of therapy. During subsequent follow-up three months later, she developed acute worsening thrombocytopenia indicative of relapsed, acute TTP. The patient was then successfully managed with PLEX and rituximab and achieved a sustained remission. DISCUSSION AND CONCLUSION TTP is a haematologic emergency that requires urgent therapy to reduce morbidity and mortality. However, it is well documented that individuals with hereditary TTP and a proportion with acquired TTP in clinical remission can have low or nearly absent ADAMTS13 activity levels without evidence of microangiopathic haemolytic anaemia (MAHA) or thrombotic manifestations. Our patient represents a unique case of confirmed ADAMTS13 deficiency due to a documented inhibitor, leading to mild haemolytic anaemia and thrombocytopenia both of which recovered spontaneously. We propose that this scenario could represent a 'subclinical' TTP state that precedes the development of clinically significant disease.
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Affiliation(s)
- Sabrina Browning
- Section of Hematology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Burak Bahar
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT, USA.,Department of Pathology and Laboratory Medicine, George Washington University, Children's National Hospital, Washington DC, USA
| | - Alfred Ian Lee
- Section of Hematology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Elan Gorshein
- Section of Hematology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
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Jacquemin M, Van Horenbeeck I, Debasse M, Toelen J, Schoeters J, Vanlinthout I, Peerlinck K, Dierickx D, Van Laer C. Optimization of the detection of inhibitory autoantibodies against the VWF-cleaving protease ADAMTS13 with an automated chemiluminescent ADAMTS13 activity immunoassay. Int J Lab Hematol 2020; 43:290-297. [PMID: 33037787 DOI: 10.1111/ijlh.13359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 09/03/2020] [Accepted: 09/16/2020] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Acquired thrombotic thrombocytopenic purpura is a rare disease associated with the production of autoantibodies against the VWF-cleaving protease ADAMTS13. The detection of these antibodies is made difficult by the instability of ADAMTS13 in citrated plasma and the time-consuming ADAMTS13 assays. The aim of our study was to evaluate the optimal conditions for detecting anti-ADAMTS13 inhibitory antibodies with the novel automated chemiluminescent immunoassay HemosILR AcuStar ADAMTS13 Activity assay. METHODS The parallelism between the AcuStar ADAMTS13 calibration curve and ADAMTS13 concentrations in serially diluted citrated plasma was evaluated after 2 hours incubation at 25°C, 37°C, or 37°C after addition of Ca2+ to preserve the activity of the metalloprotease. Using Bethesda assays based on the 3 incubation procedures and the HemosILR AcuStar ADAMTS13 Activity assay, the inhibitor titers were determined in patients' samples with ADAMTS13 antibodies and compared with those determined using the TechnozymR ADAMTS13 activity ELISA. RESULTS The criterion of parallelism was respected for the 3 incubation methods over the range of ADAMTS13 concentrations relevant for the detection of ADAMTS13 inhibitor antibodies in a Bethesda assay. In agreement with this observation, all the incubation methods permitted the accurate detection and quantification of inhibitory anti-ADAMTS13 antibodies in the samples from patients with acquired thrombotic thrombocytopenic purpura. CONCLUSION Incubation of plasma samples with normal plasma at 25°C, 37°C, or 37°C after addition of Ca2+ can be used in a Bethesda assay for quantifying the inhibitory activity of antibodies interfering with ADAMTS13 in the chemiluminescent HemosILR AcuStar ADAMTS13 Activity assay.
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Affiliation(s)
- Marc Jacquemin
- Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium.,Clinical Department of Laboratory Medicine, University Hospitals of Leuven, Leuven, Belgium
| | - Isa Van Horenbeeck
- Clinical Department of Laboratory Medicine, University Hospitals of Leuven, Leuven, Belgium
| | - Mirjam Debasse
- Clinical Department of Laboratory Medicine, University Hospitals of Leuven, Leuven, Belgium
| | - Jelle Toelen
- Clinical Department of Laboratory Medicine, University Hospitals of Leuven, Leuven, Belgium
| | - Joke Schoeters
- Clinical Department of Laboratory Medicine, University Hospitals of Leuven, Leuven, Belgium
| | - Ingrid Vanlinthout
- Clinical Department of Laboratory Medicine, University Hospitals of Leuven, Leuven, Belgium
| | - Kathelijne Peerlinck
- Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium.,Vascular Medicine and Hemostasis, University Hospitals of Leuven, Leuven, Belgium
| | - Daan Dierickx
- Clinical Department of Hematology, University Hospitals of Leuven, Leuven, Belgium
| | - Christine Van Laer
- Department of Cardiovascular Sciences, Centre for Molecular and Vascular Biology, University of Leuven, Leuven, Belgium.,Clinical Department of Laboratory Medicine, University Hospitals of Leuven, Leuven, Belgium
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Togashi K, Suzuki S, Morita S, Ogasawara Y, Imamura Y, Shin Y. Excessively activated plasminogen in human plasma cleaves VWF multimers and reduces collagen-binding activity. J Biochem 2020; 168:355-363. [DOI: 10.1093/jb/mvaa053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/16/2020] [Indexed: 12/14/2022] Open
Abstract
AbstractPlasmin (Pm) is a serine protease that can dissolve fibrin clots. Several possible functions of Pm in blood other than fibrinolysis have been proposed. To explore the effects of Pm on primary haemostasis, we evaluated the cleavage of von Willebrand factor multimers (VWFMs) in human plasma by streptokinase (SK)-activated plasminogen (Pg) and the binding ability of the digested VWFMs to collagen. SK-activated Pg and ADAMTS13 (a VWF-cleaving enzyme) in human plasma cleaved VWFMs in conformation-dependent manners through dialysis to the urea-containing buffer. However, VWFMs in human plasma under vortex-based shear stress were cleaved by SK-activated Pg but not by ADAMTS13. These results suggested that the VWFM-cleavage sites in human plasma are exposed to some extent by vortex-based shear stress for Pm but not for ADAMTS13. Additionally, we revealed that cleavage by SK-activated Pg reduced VWFMs’ binding ability to collagen, and VWFMs in human plasma were cleaved by Pm at several sites. These results suggest that SK-activated Pg degrades VWFMs, reduces their binding abilities to collagen and affects primary haemostasis. Because excessive Pg activation can degrade fibrinogen/fibrin, we propose that SK-activated Pg in blood may cause impaired primary and secondary haemostasis.
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Affiliation(s)
| | | | - Sae Morita
- Department of Chemistry and Life Science, School of Advanced Engineering, Kogakuin University, 2665-1, Nakano, Hachioji, Tokyo 1920015
| | - Yuki Ogasawara
- Department of Analytical Biochemistry, Meiji Pharmaceutical University, Tokyo, Japan
| | - Yasutada Imamura
- Graduate School of Engineering
- Department of Applied Chemistry, Faculty of Engineering
- Department of Chemistry and Life Science, School of Advanced Engineering, Kogakuin University, 2665-1, Nakano, Hachioji, Tokyo 1920015
| | - Yongchol Shin
- Graduate School of Engineering
- Department of Applied Chemistry, Faculty of Engineering
- Department of Chemistry and Life Science, School of Advanced Engineering, Kogakuin University, 2665-1, Nakano, Hachioji, Tokyo 1920015
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Bortot M, Sharifi A, Ashworth K, Walker F, Cox A, Ruegg K, Clendenen N, Neeves KB, Bark D, Di Paola J. Pathologic Shear and Elongation Rates Do Not Cause Cleavage of Von Willebrand Factor by ADAMTS13 in a Purified System. Cell Mol Bioeng 2020; 13:379-390. [PMID: 32952737 PMCID: PMC7479076 DOI: 10.1007/s12195-020-00631-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 06/18/2020] [Indexed: 01/13/2023] Open
Abstract
INTRODUCTION Pathological flows in patients with severe aortic stenosis are associated with acquired von Willebrand syndrome. This syndrome is characterized by excessive cleavage of von Willebrand factor by its main protease, A Disintegrin and Metalloproteinase with a Thrombospondin Type 1 Motif, Member 13 (ADAMTS13) leading to decreased VWF function and mucocutaneous bleeding. Aortic valve replacement and correction of the flow behavior to physiological levels reverses the syndrome, supporting the association between pathological flow and acquired von Willebrand syndrome. We investigated the effects of shear and elongational rates on von Willebrand factor cleavage in the presence of ADAMTS13. METHODS We identified acquired von Willebrand syndrome in five patients with severe aortic stenosis. Doppler echography values from these patients were used to develop three computational fluid dynamic (CFD) aortic valve models (normal, mild and severe stenosis). Shear, elongational rates and exposure times identified in the CFD simulations were used as parameters for the design of microfluidic devices to test the effects of pathologic shear and elongational rates on the structure and function of von Willebrand factor. RESULTS The shear rates (0-10,000s-1), elongational rates (0-1000 s-1) and exposure times (1-180 ms) tested in our microfluidic designs mimicked the flow features identified in patients with aortic stenosis. The shear and elongational rates tested in vitro did not lead to excessive cleavage or decreased function of von Willebrand factor in the presence of the protease. CONCLUSIONS High shear and elongational rates in the presence of ADAMTS13 are not sufficient for excessive cleavage of von Willebrand Factor.
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Affiliation(s)
- Maria Bortot
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 USA
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 USA
| | - Alireza Sharifi
- Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523 USA
| | - Katrina Ashworth
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 USA
| | - Faye Walker
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 USA
| | - Allaura Cox
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 USA
| | - Katherine Ruegg
- Hemophilia Center, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 USA
| | - Nathan Clendenen
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 USA
| | - Keith B. Neeves
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 USA
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 USA
| | - David Bark
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 USA
- Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523 USA
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523 USA
| | - Jorge Di Paola
- Department of Pediatrics, Washington University in St. Louis, 660 S. Euclid Avenue, Campus Box 8208, 5th floor MPRB, St. Louis, MO 63110 USA
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10
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von Willebrand factor self-association is regulated by the shear-dependent unfolding of the A2 domain. Blood Adv 2020; 3:957-968. [PMID: 30936056 DOI: 10.1182/bloodadvances.2018030122] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 02/17/2019] [Indexed: 11/20/2022] Open
Abstract
von Willebrand factor (VWF) self-association results in the homotypic binding of VWF upon exposure to fluid shear. The molecular mechanism of this process is not established. In this study, we demonstrate that the shear-dependent unfolding of the VWF A2 domain in the multimeric protein is a major regulator of protein self-association. This mechanism controls self-association on the platelet glycoprotein Ibα receptor, on collagen substrates, and during thrombus growth ex vivo. In support of this, A2-domain mutations that prevent domain unfolding due to disulfide bridging of N- and C-terminal residues ("Lock-VWF") reduce self-association and platelet activation under various experimental conditions. In contrast, reducing assay calcium concentrations, and 2 mutations that destabilize VWF-A2 conformation by preventing coordination with calcium (D1498A and R1597W VWD type 2A mutation), enhance self-association. Studies using a panel of recombinant proteins that lack the A1 domain ("ΔA1 proteins") suggest that besides pure homotypic A2 interactions, VWF-A2 may also engage other protein domains to control self-association. Addition of purified high-density lipoprotein and apolipoprotein-A1 partially blocked VWF self-association. Overall, similar conditions facilitate VWF self-association and ADAMTS13-mediated proteolysis, with low calcium and A2 disease mutations enhancing both processes, and locking-A2 blocking them simultaneously. Thus, VWF appears to have evolved 2 balancing molecular functions in a single A2 functional domain to dynamically regulate protein size in circulation: ADAMTS13-mediated proteolysis and VWF self-association. Modulating self-association rates by targeting VWF-A2 may provide novel methods to regulate the rates of thrombosis and hemostasis.
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11
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Varatharajah N, Rajah S. Microthrombotic Complications of COVID-19 Are Likely Due to Embolism of Circulating Endothelial Derived Ultralarge Von Willebrand Factor (eULVWF) Decorated-Platelet Strings. Fed Pract 2020; 37:e1-e2. [PMID: 32489244 PMCID: PMC7241602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
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12
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Varatharajah N, Rajah S. Microthrombotic Complications of COVID-19 Are Likely Due to Embolism of Circulating Endothelial Derived Ultralarge von Willebrand Factor (eULVWF) Decorated-Platelet Strings. Fed Pract 2020; 37:258-259. [PMID: 32669777 PMCID: PMC7357889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
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13
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Abstract
ADAMTS7 is a secreted protease that is predominantly expressed in tissues of the cardiovascular system and tendon. Although recent evidence suggests that it may play a role in the etiology of coronary artery disease, its physiological function and substrates are unknown. The enzyme undergoes extensive posttranslational modifications, including chondroitin sulfate attachment, N and O-linked glycosylation, and a two-step activation process. For the benefit of scientists who study the function of ADAMTS7 and its role in disease, this chapter provides an introduction to the chemical and functional properties of the various ADAMTS7 domains, as well as a protocol for the recombinant expression and purification of ADAMTS7.
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Affiliation(s)
- Rens de Groot
- Center for Hematology, Imperial College, London, UK.
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14
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Bortot M, Ashworth K, Sharifi A, Walker F, Crawford NC, Neeves KB, Bark D, Di Paola J. Turbulent Flow Promotes Cleavage of VWF (von Willebrand Factor) by ADAMTS13 (A Disintegrin and Metalloproteinase With a Thrombospondin Type-1 Motif, Member 13). Arterioscler Thromb Vasc Biol 2019; 39:1831-1842. [DOI: 10.1161/atvbaha.119.312814] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Objective—
Acquired von Willebrand syndrome is defined by excessive cleavage of the VWF (von Willebrand Factor) and is associated with impaired primary hemostasis and severe bleeding. It often develops when blood is exposed to nonphysiological flow such as in aortic stenosis or mechanical circulatory support. We evaluated the role of laminar, transitional, and turbulent flow on VWF cleavage and the effects on VWF function.
Approach and Results—
We used a vane rheometer to generate laminar, transitional, and turbulent flow and evaluate the effect of each on VWF cleavage in the presence of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type-1 motif, member 13). We performed functional assays to evaluate the effect of these flows on VWF structure and function. Computational fluid dynamics was used to estimate the flow fields and forces within the vane rheometer under each flow condition. Turbulent flow is required for excessive cleavage of VWF in an ADAMTS13-dependent manner. The assay was repeated with whole blood, and the turbulent flow had the same effect. Our computational fluid dynamics results show that under turbulent conditions, the Kolmogorov scale approaches the size of VWF. Finally, cleavage of VWF in this study has functional consequences under flow as the resulting VWF has decreased ability to bind platelets and collagen.
Conclusions—
Turbulent flow mediates VWF cleavage in the presence of ADAMTS13, decreasing the ability of VWF to sustain platelet adhesion. These findings impact the design of mechanical circulatory support devices and are relevant to pathological environments where turbulence is added to circulation.
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Affiliation(s)
- Maria Bortot
- From the Department of Pediatrics (M.B., K.A., F.W., K.B.N., D.B., J.D.P.), University of Colorado Anschutz Medical Campus, Aurora
- Department of Bioengineering (M.B., K.B.N.), University of Colorado Anschutz Medical Campus, Aurora
| | - Katrina Ashworth
- From the Department of Pediatrics (M.B., K.A., F.W., K.B.N., D.B., J.D.P.), University of Colorado Anschutz Medical Campus, Aurora
| | - Alireza Sharifi
- Department of Mechanical Engineering (A.S., D.B.), Colorado State University, Fort Collins
| | - Faye Walker
- From the Department of Pediatrics (M.B., K.A., F.W., K.B.N., D.B., J.D.P.), University of Colorado Anschutz Medical Campus, Aurora
| | - Nathan C. Crawford
- Department of Material Characterization, Thermo Fisher Scientific, Madison, WI (N.C.C.)
| | - Keith B. Neeves
- From the Department of Pediatrics (M.B., K.A., F.W., K.B.N., D.B., J.D.P.), University of Colorado Anschutz Medical Campus, Aurora
- Department of Bioengineering (M.B., K.B.N.), University of Colorado Anschutz Medical Campus, Aurora
| | - David Bark
- From the Department of Pediatrics (M.B., K.A., F.W., K.B.N., D.B., J.D.P.), University of Colorado Anschutz Medical Campus, Aurora
- Department of Mechanical Engineering (A.S., D.B.), Colorado State University, Fort Collins
- School of Biomedical Engineering (D.B.), Colorado State University, Fort Collins
| | - Jorge Di Paola
- From the Department of Pediatrics (M.B., K.A., F.W., K.B.N., D.B., J.D.P.), University of Colorado Anschutz Medical Campus, Aurora
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15
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Rottensteiner H, Kaufmann S, Rathgeb A, Kink B, Plaimauer B, Matthiessen P, Hann S, Scheiflinger F. Temperature-dependent irreversible conformational change of recombinant ADAMTS13 upon metal ion chelation. J Thromb Haemost 2019; 17:995-1002. [PMID: 31006963 PMCID: PMC6850365 DOI: 10.1111/jth.14440] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 03/20/2019] [Indexed: 01/18/2023]
Abstract
BACKGROUND The catalytic domain of ADAMTS13 possesses one Zn2+ and up to three putative Ca2+ binding sites and can be inactivated by chelating agents. Although replenishment with an appropriate metallic cation is thought to restore the enzyme's proteolytic activity fully, ADAMTS13 stability in a metal ion-depleting environment has not been explored. OBJECTIVES To address the stability of ADAMTS13 in citrated human plasma. METHODS ADAMTS13 activity was measured using the FRETS-VWF73 fluorogenic assay. The molar ratio of metals bound to ADAMTS13 was determined by size exclusion chromatography inductively coupled plasma mass spectrometry (SEC-ICP-MS). Higher-order structural changes were analyzed using Fourier-transformed infrared spectroscopy and dynamic light scattering. RESULTS ADAMTS13 was stable at room temperature for up to 24 hours irrespective of the presence of citrate (0.38%). However, at 37°C, citrate caused a time-dependent activity decrease. No ADAMTS13 activity decrease was seen in heparinized plasma, but the addition of citrate again caused ADAMTS13 instability at 37°C. Scavenging of citrate by the addition of Ca2+ or Zn2+ prior to but not postincubation prevented the activity decrease of the enzyme. The SEC-ICP-MS analyses showed that ADAMTS13 only bound Zn2+ and that its reduced activity correlated with a gradual loss of bound Zn2+ . Concomitant higher-order structural analyses demonstrated structural changes in ADAMTS13 that are typical of less-ordered protein structures. CONCLUSIONS Zn2+ is required to stabilize ADAMTS13 structure at physiologic temperature, thereby preventing irreversible loss of enzyme activity. This finding is particularly important to consider when using citrated human plasma as a source of ADAMTS13 in clinical settings.
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Affiliation(s)
| | - Stefan Kaufmann
- Baxalta Innovations GmbH, a member of the Takeda group of companiesViennaAustria
| | - Anna Rathgeb
- Department of ChemistryUniversity of Natural Resources and Life Sciences (BOKU)ViennaAustria
| | - Barbara Kink
- Baxalta Innovations GmbH, a member of the Takeda group of companiesViennaAustria
| | - Barbara Plaimauer
- Baxalta Innovations GmbH, a member of the Takeda group of companiesViennaAustria
| | - Peter Matthiessen
- Baxalta Innovations GmbH, a member of the Takeda group of companiesViennaAustria
| | - Stephan Hann
- Department of ChemistryUniversity of Natural Resources and Life Sciences (BOKU)ViennaAustria
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16
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Zhu J, Muia J, Gupta G, Westfield LA, Vanhoorelbeke K, Tolia NH, Sadler JE. Exploring the "minimal" structure of a functional ADAMTS13 by mutagenesis and small-angle X-ray scattering. Blood 2019; 133:1909-1918. [PMID: 30692120 PMCID: PMC6484386 DOI: 10.1182/blood-2018-11-886309] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/20/2019] [Indexed: 12/18/2022] Open
Abstract
Human ADAMTS13 is a multidomain protein with metalloprotease (M), disintegrin-like (D), thrombospondin-1 (T), Cys-rich (C), and spacer (S) domains, followed by 7 additional T domains and 2 CUB (complement components C1r and C1s, sea urchin protein Uegf, and bone morphogenetic protein-1) domains. ADAMTS13 inhibits the growth of von Willebrand factor (VWF)-platelet aggregates by cleaving the cryptic Tyr1605-Met1606 bond in the VWF A2 domain. ADAMTS13 is regulated by substrate-induced allosteric activation; without shear stress, the distal T8-CUB domains markedly inhibit VWF cleavage, and binding of VWF domain D4 or selected monoclonal antibodies (MAbs) to distal ADAMTS13 domains relieves this autoinhibition. By small angle X-ray scattering (SAXS), ADAMTS13 adopts a hairpin-like conformation with distal T7-CUB domains close to the proximal MDTCS domains and a hinge point between T4 and T5. The hairpin projects like a handle away from the core MDTCS and T7-CUB complex and contains distal T domains that are dispensable for allosteric regulation. Truncated constructs that lack the T8-CUB domains are not autoinhibited and cannot be activated by VWF D4 but retain the hairpin fold. Allosteric activation by VWF D4 requires T7, T8, and the 58-amino acid residue linker between T8 and CUB1. Deletion of T3 to T6 produced the smallest construct (delT3-6) examined that could be activated by MAbs and VWF D4. Columba livia (pigeon) ADAMTS13 (pADAMTS13) resembles human delT3-6, retains normal activation by VWF D4, and has a SAXS envelope consistent with amputation of the hairpin containing the dispensable T domains of human ADAMTS13. Our findings suggest that human delT3-6 and pADAMTS13 approach a "minimal" structure for allosterically regulated ADAMTS13.
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Affiliation(s)
- Jian Zhu
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Joshua Muia
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Garima Gupta
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Lisa A Westfield
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
| | - Karen Vanhoorelbeke
- Laboratory for Thrombosis Research, Interdisciplinary Research Facility Life Sciences, Katholieke Universiteit Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - Niraj H Tolia
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rockville, MD; and
| | - J Evan Sadler
- Department of Medicine, Washington University School of Medicine, St. Louis, MO
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
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17
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Phylogenetic and functional analysis of ADAMTS13 identifies highly conserved domains essential for allosteric regulation. Blood 2019; 133:1899-1908. [PMID: 30700419 DOI: 10.1182/blood-2018-11-886275] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 01/20/2019] [Indexed: 12/18/2022] Open
Abstract
The metalloprotease ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 repeats member 13) prevents microvascular thrombosis by cleaving von Willebrand factor (VWF) within platelet-rich thrombi, and cleavage depends on allosteric activation of ADAMTS13 by the substrate VWF. Human ADAMTS13 has a short propeptide, metalloprotease (M), disintegrin-like (D), thrombospondin-1 (T), Cys-rich (C), and spacer (S) domains (proximal domains), followed by 7 T and 2 CUB (complement components C1r and C1s, sea urchin protein Uegf, and bone morphogenetic protein-1) domains (distal domains). Distal domains inhibit the catalytic proximal domains; binding of distal T8-CUB domains to the VWF D4 domain relieves autoinhibition and promotes cleavage of the nearby VWF A2 domain. However, the role of specific ADAMTS13 distal domains in this allosteric mechanism is not established. Assays of plasma ADAMTS13 from 20 placental mammals, birds, and amphibians show that allosteric regulation is broadly conserved, and phylogenetic analysis of 264 vertebrates shows the long propeptide, T3, T4, T6, and T6a domains have been deleted several times in placental mammals, birds, and fish. Notably, pigeon ADAMTS13 has only 3 distal T domains but was activated normally by human VWF D4 and cleaved VWF multimers, preferentially under fluid shear stress. Human ADAMTS13 constructed to resemble pigeon ADAMTS13 retained normal allosteric regulation and shear-dependent cleavage of VWF. Thus, the T3-T6 domains of human ADAMTS13 are dispensable. Conversely, deletion of T7 or T8 abolished allosteric activation. For most species, some sequence changes in the VWF substrate can markedly increase the rate of cleavage, suggesting that ADAMTS13 and VWF have not evolved to be optimal enzyme-substrate pairs. These properties may reflect evolutionary pressure to balance the risk for VWF-dependent bleeding and thrombosis.
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18
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Plautz WE, Raval JS, Dyer MR, Rollins-Raval MA, Zuckerbraun BS, Neal MD. ADAMTS13: origins, applications, and prospects. Transfusion 2018; 58:2453-2462. [PMID: 30208220 DOI: 10.1111/trf.14804] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/16/2018] [Accepted: 04/16/2018] [Indexed: 12/14/2022]
Abstract
ADAMTS13 is an enzyme that acts by cleaving prothrombotic von Willebrand factor (VWF) multimers from the vasculature in a highly regulated manner. In pathologic states such as thrombotic thrombocytopenic purpura (TTP) and other thrombotic microangiopathies (TMAs), VWF can bind to the endothelium and form large multimers. As the anchored VWF chains grow, they provide a greater surface area to bind circulating platelets (PLTs), generating unique thrombi that characterize TTP. This results in microvasculature thrombosis, obstruction of blood flow, and ultimately end-organ damage. Initial presentations of TTP usually occur in an acute manner, typically developing due to an autoimmune response toward, or less commonly a congenital deficiency of, ADAMTS13. Triggers for TMAs that can be associated with ADAMTS13 deficiency, including TTP, have been linked to events that place a burden on hemostatic regulation, such as major trauma and pregnancy. The treatment plan for cases of suspected TTP consists of emergent therapeutic plasma exchange that is continued on a daily basis until normalization of PLT counts. However, a subset of these patients does not respond favorably to standard therapies. These patients necessitate a better understanding of their diseases for the advancement of future therapeutic options. Given ADAMTS13's key role in the cleavage of VWF and the prevention of PLT-rich thrombi within the microvasculature, future treatments may include anti-VWF therapeutics, recombinant ADAMTS13 infusions, and ADAMTS13 expression via gene therapy.
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Affiliation(s)
- William E Plautz
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Jay S Raval
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Mitchell R Dyer
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Marian A Rollins-Raval
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Brian S Zuckerbraun
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Matthew D Neal
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
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19
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Wong KHK, Edd JF, Tessier SN, Moyo WD, Mutlu BR, Bookstaver LD, Miller KL, Herrara S, Stott SL, Toner M. Anti-thrombotic strategies for microfluidic blood processing. LAB ON A CHIP 2018; 18:2146-2155. [PMID: 29938257 PMCID: PMC6082414 DOI: 10.1039/c8lc00035b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The redundant mechanisms involved in blood coagulation are crucial for rapid hemostasis. Yet they also create challenges in blood processing in medical devices and lab-on-a-chip systems. In this work, we investigate the effects of both shear stress and hypothermic blood storage on thrombus formation in microfluidic processing. For fresh blood, thrombosis occurs only at high shear, and the glycoprotein IIb/IIIa inhibitor tirofiban is highly effective in preventing thrombus formation. Blood storage generally activates platelets and primes them towards thrombosis via multiple mechanisms. Thrombus formation of stored blood at low shear can be adequately inhibited by glycoprotein IIb/IIIa inhibitors. At high shear, von Willebrand factor-mediated thrombosis contributes significantly and requires additional treatments with thiol-containing antioxidants-such as N acetylcysteine and reduced glutathione-that interfere with von Willebrand factor polymerization. We further demonstrate the effectiveness of these anti-thrombotic strategies in microfluidic devices made of cyclic olefin copolymer, a popular material used in the healthcare industry. This work identifies effective anti-thrombotic strategies that are applicable in a wide range of blood- and organ-on-a-chip applications.
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Affiliation(s)
- Keith H. K. Wong
- BioMEMS Resource Center, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Jon F. Edd
- BioMEMS Resource Center, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Shannon N. Tessier
- BioMEMS Resource Center, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Will D. Moyo
- BioMEMS Resource Center, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Baris R. Mutlu
- BioMEMS Resource Center, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Lauren D. Bookstaver
- BioMEMS Resource Center, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Kathleen L. Miller
- BioMEMS Resource Center, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Stefan Herrara
- BioMEMS Resource Center, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Cancer Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Shannon L. Stott
- BioMEMS Resource Center, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Cancer Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Corresponding author. (M.T.); (S.L.S.)
| | - Mehmet Toner
- BioMEMS Resource Center, Center for Engineering in Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
- Corresponding author. (M.T.); (S.L.S.)
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20
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Kretz CA, Tomberg K, Van Esbroeck A, Yee A, Ginsburg D. High throughput protease profiling comprehensively defines active site specificity for thrombin and ADAMTS13. Sci Rep 2018; 8:2788. [PMID: 29434246 PMCID: PMC5809430 DOI: 10.1038/s41598-018-21021-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 01/29/2018] [Indexed: 12/20/2022] Open
Abstract
We have combined random 6 amino acid substrate phage display with high throughput sequencing to comprehensively define the active site specificity of the serine protease thrombin and the metalloprotease ADAMTS13. The substrate motif for thrombin was determined by >6,700 cleaved peptides, and was highly concordant with previous studies. In contrast, ADAMTS13 cleaved only 96 peptides (out of >107 sequences), with no apparent consensus motif. However, when the hexapeptide library was substituted into the P3-P3′ interval of VWF73, an exosite-engaging substrate of ADAMTS13, 1670 unique peptides were cleaved. ADAMTS13 exhibited a general preference for aliphatic amino acids throughout the P3-P3′ interval, except at P2 where Arg was tolerated. The cleaved peptides assembled into a motif dominated by P3 Leu, and bulky aliphatic residues at P1 and P1′. Overall, the P3-P2′ amino acid sequence of von Willebrand Factor appears optimally evolved for ADAMTS13 recognition. These data confirm the critical role of exosite engagement for substrates to gain access to the active site of ADAMTS13, and define the substrate recognition motif for ADAMTS13. Combining substrate phage display with high throughput sequencing is a powerful approach for comprehensively defining the active site specificity of proteases.
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Affiliation(s)
- Colin A Kretz
- Department of Medicine, McMaster University and the Thrombosis and Atherosclerosis Research Institute, Hamilton, Ontario, Canada.
| | - Kärt Tomberg
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Alexander Van Esbroeck
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
| | - Andrew Yee
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - David Ginsburg
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.,Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA.,Howard Hughes Medical Institute and Departments of Internal Medicine and Pediatrics, University of Michigan, Ann Arbor, MI, USA
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21
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Roose E, Schelpe AS, Joly BS, Peetermans M, Verhamme P, Voorberg J, Greinacher A, Deckmyn H, De Meyer SF, Coppo P, Veyradier A, Vanhoorelbeke K. An open conformation of ADAMTS-13 is a hallmark of acute acquired thrombotic thrombocytopenic purpura. J Thromb Haemost 2018; 16:378-388. [PMID: 29222940 DOI: 10.1111/jth.13922] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Indexed: 12/20/2022]
Abstract
Essentials Conformational changes in ADAMTS-13 are part of its mode-of-action. The murine anti-ADAMTS-13 antibody 1C4 discriminates between folded and open ADAMTS-13. ADAMTS-13 conformation is open in acute acquired thrombotic thrombocytopenic purpura (TTP). Our study forms an important basis to fully elucidate the pathophysiology of TTP. SUMMARY Background Acquired thrombotic thrombocytopenic purpura (aTTP) is an autoimmune disorder characterized by absent ADAMTS-13 activity and the presence of anti-ADAMTS-13 autoantibodies. Recently, it was shown that ADAMTS-13 adopts a folded or an open conformation. Objectives As conformational changes in self-antigens play a role in the pathophysiology of different autoimmune diseases, we hypothesized that the conformation of ADAMTS-13 changes during acute aTTP. Methods Antibodies recognizing cryptic epitopes in the spacer domain were generated. Next, the conformation of ADAMTS-13 in 40 healthy donors (HDs), 99 aTTP patients (63 in the acute phase versus 36 in remission), 12 hemolytic-uremic syndrome (HUS) patients and 63 sepsis patients was determined with ELISA. Results The antibody 1C4 recognizes a cryptic epitope in ADAMTS-13. Therefore, we were able to discriminate between a folded and an open ADAMTS-13 conformation. We showed that ADAMTS-13 in HDs does not bind to 1C4, indicating that ADAMTS-13 circulates in a folded conformation. Similar results were obtained for HUS and sepsis patients. In contrast, ADAMTS-13 of acute aTTP patients bound to 1C4 in 92% of the cases, whereas, in most cases, this binding was abolished during remission, showing that the conformation of ADAMTS-13 is open during an acute aTTP episode. Conclusions Our study shows that, besides absent ADAMTS-13 activity and the presence of anti-ADAMTS-13 autoantibodies, an open ADAMTS-13 conformation is also a hallmark of acute aTTP. Demonstrating this altered ADAMTS-13 conformation in acute aTTP will help to further unravel the pathophysiology of aTTP and lead to improved therapy and diagnosis.
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Affiliation(s)
- E Roose
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - A S Schelpe
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - B S Joly
- Service d'Hématologie biologique, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris and EA3518, Institut Universitaire d'Hématologie, Hôpital Saint Louis, Université Paris Diderot, Paris, France
| | - M Peetermans
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - P Verhamme
- Center for Molecular and Vascular Biology, Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - J Voorberg
- Department of Plasma Proteins, Sanquin-Academic Medical Center Landsteiner Laboratory, Amsterdam, the Netherlands
| | - A Greinacher
- Institute for Immunology and Transfusion Medicine, University Medical Center, Greifswald, Germany
| | - H Deckmyn
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - S F De Meyer
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - P Coppo
- Département d'hématologie clinique, Hôpital Saint Antoine, AP-HP and Université Pierre et Marie Curie, Paris, France
| | - A Veyradier
- Service d'Hématologie biologique, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris and EA3518, Institut Universitaire d'Hématologie, Hôpital Saint Louis, Université Paris Diderot, Paris, France
| | - K Vanhoorelbeke
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
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22
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Abstract
von Willebrand factor (VWF) is a key player in hemostasis, acting as a carrier for factor VIII and capturing platelets at sites of vascular damage. To capture platelets, it must undergo conformational changes, both within its A1 domain and at the macromolecular level through A2 domain unfolding. Its size and this function are regulated by the metalloproteinase ADAMTS-13. Recently, it has been shown that ADAMTS-13 undergoes a conformational change upon interaction with VWF, and that this enhances its activity towards its substrate. This review summarizes recent work on these conformational transitions, describing how they are controlled. It points to their importance in hemostasis, bleeding disorders, and the developing field of therapeutic application of ADAMTS-13 as an antithrombotic agent in obstructive microvascular thrombosis and in cardiovascular disease.
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Affiliation(s)
- K. South
- Centre for HaematologyImperial College LondonLondonUK
| | - D. A. Lane
- Centre for HaematologyImperial College LondonLondonUK
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Role of calcium in regulating the intra- and extracellular cleavage of von Willebrand factor by the protease ADAMTS13. Blood Adv 2017; 1:2063-2074. [PMID: 29296853 DOI: 10.1182/bloodadvances.2017009027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 09/23/2017] [Indexed: 11/20/2022] Open
Abstract
von Willebrand factor (VWF) and the metalloprotease a disintegrin and metalloprotease with thrombospondin type 1 motif 13 (ADAMTS13) are present both within endothelial cells (ECs) and in peripheral blood. Calcium concentrations are lower in intracellular compartments (80-400 μM) compared with the extracellular milieu (∼1.25 mM). Because low calcium favors VWF A2-domain proteolysis by ADAMTS13, the dependence of proteolysis rates on calcium was assayed both within ECs and in blood. Confocal microscopy studies demonstrate partial perinuclear colocalization of VWF with ADAMTS13 in human umbilical vein ECs (HUVECs). Consequently, low levels (5%-10%) of VWF cleavage products were detected in HUVEC lysates and also culture-supernatant following EC stimulation. This proteolysis occurred before disulfide bond formation. Compared with wild-type VWF A2-domain, calcium-binding mutants including the common von Willebrand disease (VWD) type 2A R1597W mutant were expressed in an open conformation in ECs and were highly susceptible to intracellular proteolysis. Fluorescence resonance energy transfer measurements demonstrate strong calcium-dependent VWF-A2 conformation changes at concentrations <500 μM, with unfolding rates being fourfold higher for monomeric VWF A2-domain compared with multimeric, full-length VWF. Under shear, physiological levels of ADAMTS13 did not cleave VWF strings on HUVECs, unless platelets were attached to stretch these strings under flow. Further, VWF-platelet string cleavage under shear proceeded with equal efficiency in the absence and presence of calcium at shear stress ≥1 dyn/cm2. Overall, low calcium levels may promote intracellular VWF proteolysis particularly during VWD type 2A disease. Calcium has a negligible effect on VWF-platelet string proteolysis under physiologically relevant fluid shear.
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Bettoni S, Galbusera M, Gastoldi S, Donadelli R, Tentori C, Spartà G, Bresin E, Mele C, Alberti M, Tortajada A, Yebenes H, Remuzzi G, Noris M. Interaction between Multimeric von Willebrand Factor and Complement: A Fresh Look to the Pathophysiology of Microvascular Thrombosis. THE JOURNAL OF IMMUNOLOGY 2017; 199:1021-1040. [PMID: 28652401 DOI: 10.4049/jimmunol.1601121] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 05/23/2017] [Indexed: 12/18/2022]
Abstract
von Willebrand factor (VWF), a multimeric protein with a central role in hemostasis, has been shown to interact with complement components. However, results are contrasting and inconclusive. By studying 20 patients with congenital thrombotic thrombocytopenic purpura (cTTP) who cannot cleave VWF multimers because of genetic ADAMTS13 deficiency, we investigated the mechanism through which VWF modulates complement and its pathophysiological implications for human diseases. Using assays of ex vivo serum-induced C3 and C5b-9 deposits on endothelial cells, we documented that in cTTP, complement is activated via the alternative pathway (AP) on the cell surface. This abnormality was corrected by restoring ADAMTS13 activity in cTTP serum, which prevented VWF multimer accumulation on endothelial cells, or by an anti-VWF Ab. In mechanistic studies we found that VWF interacts with C3b through its three type A domains and initiates AP activation, although assembly of active C5 convertase and formation of the terminal complement products C5a and C5b-9 occur only on the VWF-A2 domain. Finally, we documented that in the condition of ADAMTS13 deficiency, VWF-mediated formation of terminal complement products, particularly C5a, alters the endothelial antithrombogenic properties and induces microvascular thrombosis in a perfusion system. Altogether, the results demonstrated that VWF provides a platform for the activation of the AP of complement, which profoundly alters the phenotype of microvascular endothelial cells. These findings link hemostasis-thrombosis with the AP of complement and open new therapeutic perspectives in cTTP and in general in thrombotic and inflammatory disorders associated with endothelium perturbation, VWF release, and complement activation.
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Affiliation(s)
- Serena Bettoni
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy
| | - Miriam Galbusera
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy
| | - Sara Gastoldi
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy
| | - Roberta Donadelli
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy
| | - Chiara Tentori
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy
| | - Giuseppina Spartà
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy
| | - Elena Bresin
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy
| | - Caterina Mele
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy
| | - Marta Alberti
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy
| | - Agustin Tortajada
- Department of Immunology, Complutense University, Research Institute Hospital 12 de Octubre, 28040 Madrid, Spain
| | - Hugo Yebenes
- Departamento de Medicina Celular y Molecular, Centro de Investigaciones Biologicas, 28040 Madrid, Spain
| | - Giuseppe Remuzzi
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy; .,Unità di Nefrologia e Dialisi, Azienda Ospedaliera Papa Giovanni XXIII, 24127 Bergamo, Italy; and.,Department of Biomedical and Clinical Sciences, University of Milan, 20157 Milan, Italy
| | - Marina Noris
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri," Centro di Ricerche Cliniche per le Malattie Rare "Aldo e Cele Daccò," 24020 Ranica Bergamo, Italy
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Cote R, Lynn Eggink L, Kenneth Hoober J. CLEC receptors, endocytosis and calcium signaling. AIMS ALLERGY AND IMMUNOLOGY 2017. [DOI: 10.3934/allergy.2017.4.207] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Deforche L, Roose E, Vandenbulcke A, Vandeputte N, Feys HB, Springer TA, Mi LZ, Muia J, Sadler JE, Soejima K, Rottensteiner H, Deckmyn H, De Meyer SF, Vanhoorelbeke K. Linker regions and flexibility around the metalloprotease domain account for conformational activation of ADAMTS-13. J Thromb Haemost 2015; 13:2063-75. [PMID: 26391536 PMCID: PMC4778570 DOI: 10.1111/jth.13149] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 09/05/2015] [Indexed: 12/29/2022]
Abstract
BACKGROUND Recently, conformational activation of ADAMTS-13 was identified. This mechanism showed the evolution from a condensed conformation, in which the proximal MDTCS and distal T2-CUB2 domains are in close contact with each other, to an activated, open structure due to binding with von Willebrand factor (VWF). OBJECTIVES Identification of cryptic epitope/exosite exposure after conformational activation and of sites of flexibility in ADAMTS-13. METHODS The activating effect of 25 anti-T2-CUB2 antibodies was studied in the FRETS-VWF73 and the vortex assay. Cryptic epitope/exosite exposure was determined with ELISA and VWF binding assay. The molecular basis for flexibility was hypothesized through rapid automatic detection and alignment of repeats (RADAR) analysis, tested with ELISA using deletion variants and visualized using electron microscopy. RESULTS Eleven activating anti-ADAMTS-13 antibodies, directed against the T5-CUB2 domains, were identified in the FRETS-VWF73 assay. RADAR analysis identified three linker regions in the distal domains. Interestingly, identification of an antibody recognizing a cryptic epitope in the metalloprotease domain confirmed the contribution of these linker regions to conformational activation of the enzyme. The proof of flexibility around both the T2 and metalloprotease domains, as shown by by electron microscopy, further supported this contribution. In addition, cryptic epitope exposure was identified in the distal domains, because activating anti-T2-CUB2 antibodies increased the binding to folded VWF up to ~3-fold. CONCLUSION Conformational activation of ADAMTS-13 leads to cryptic epitope/exosite exposure in both proximal and distal domains, subsequently inducing increased activity. Furthermore, three linker regions in the distal domains are responsible for flexibility and enable the interaction between the proximal and the T8-CUB2 domains.
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Affiliation(s)
- L Deforche
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Kulak, Kortrijk, Belgium
| | - E Roose
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Kulak, Kortrijk, Belgium
| | - A Vandenbulcke
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Kulak, Kortrijk, Belgium
| | - N Vandeputte
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Kulak, Kortrijk, Belgium
| | - H B Feys
- Transfusion Research Center, Belgian Red Cross Flanders, Gent, Belgium
| | - T A Springer
- Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - L Z Mi
- Program in Cellular and Molecular Medicine, Boston Children's Hospital and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - J Muia
- Departments of Medicine, Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, MO, USA
| | - J E Sadler
- Departments of Medicine, Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, MO, USA
| | - K Soejima
- Research Department 1, The Chemo-Sero-Therapeutic Research Institute, Kikuchi, Kumamoto, Japan
| | | | - H Deckmyn
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Kulak, Kortrijk, Belgium
| | - S F De Meyer
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Kulak, Kortrijk, Belgium
| | - K Vanhoorelbeke
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Kulak, Kortrijk, Belgium
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Pinto-Almeida A, Mendes T, Armada A, Belo S, Carrilho E, Viveiros M, Afonso A. The Role of Efflux Pumps in Schistosoma mansoni Praziquantel Resistant Phenotype. PLoS One 2015; 10:e0140147. [PMID: 26445012 PMCID: PMC4596880 DOI: 10.1371/journal.pone.0140147] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 09/21/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Schistosomiasis is a neglected disease caused by a trematode of the genus Schistosoma that is second only to malaria in public health significance in Africa, South America, and Asia. Praziquantel (PZQ) is the drug of choice to treat this disease due to its high cure rates and no significant side effects. However, in the last years increasingly cases of tolerance to PZQ have been reported, which has caused growing concerns regarding the emergency of resistance to this drug. METHODOLOGY/PRINCIPAL FINDINGS Here we describe the selection of a parasitic strain that has a stable resistance phenotype to PZQ. It has been reported that drug resistance in helminths might involve efflux pumps such as members of ATP-binding cassette transport proteins, including P-glycoprotein and multidrug resistance-associated protein families. Here we evaluate the role of efflux pumps in Schistosoma mansoni resistance to PZQ, by comparing the efflux pumps activity in susceptible and resistant strains. The evaluation of the efflux activity was performed by an ethidium bromide accumulation assay in presence and absence of Verapamil. The role of efflux pumps in resistance to PZQ was further investigated comparing the response of susceptible and resistant parasites in the absence and presence of different doses of Verapamil, in an ex vivo assay, and these results were further reinforced through the comparison of the expression levels of SmMDR2 RNA by RT-PCR. CONCLUSIONS/SIGNIFICANCE This work strongly suggests the involvement of Pgp-like transporters SMDR2 in Praziquantel drug resistance in S. mansoni. Low doses of Verapamil successfully reverted drug resistance. Our results might give an indication that a combination therapy with PZQ and natural or synthetic Pgp modulators can be an effective strategy for the treatment of confirmed cases of resistance to PZQ in S. mansoni.
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Affiliation(s)
- António Pinto-Almeida
- Graduate Program in Areas of Basic and Applied Biology, Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
- Medical Parasitology Unit, Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
- Universidade de São Paulo, Instituto de Química de São Carlos, São Carlos, SP, Brazil
| | - Tiago Mendes
- Medical Parasitology Unit, Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
- Institute of Biology, Universidade de Campinas, Campinas, SP, Brazil
| | - Ana Armada
- Medical Microbiology Unit, Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
| | - Silvana Belo
- Medical Parasitology Unit, Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
| | - Emanuel Carrilho
- Universidade de São Paulo, Instituto de Química de São Carlos, São Carlos, SP, Brazil
| | - Miguel Viveiros
- Medical Microbiology Unit, Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
| | - Ana Afonso
- Medical Parasitology Unit, Global Health and Tropical Medicine, GHTM, Instituto de Higiene e Medicina Tropical, IHMT, Universidade Nova de Lisboa, UNL, Lisbon, Portugal
- Universidade de São Paulo, Instituto de Química de São Carlos, São Carlos, SP, Brazil
- Laboratory of Parasitology, Departamento de Morfologia e Patologia, Universidade Federal de São Carlos, São Carlos, SP, Brazil
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Bonazza K, Rottensteiner H, Schrenk G, Frank J, Allmaier G, Turecek PL, Scheiflinger F, Friedbacher G. Shear-Dependent Interactions of von Willebrand Factor with Factor VIII and Protease ADAMTS 13 Demonstrated at a Single Molecule Level by Atomic Force Microscopy. Anal Chem 2015; 87:10299-305. [PMID: 26369694 DOI: 10.1021/acs.analchem.5b02078] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Vital functions of mammals are only possible due to the behavior of blood to coagulate most efficiently in vessels with particularly high wall shear rates. This is caused by the functional changes of the von Willebrand Factor (VWF), which mediates coagulation of blood platelets (primary hemostasis) especially when it is stretched under shear stress. Our data show that shear stretching also affects other functions of VWF: Using a customized device to simulate shear conditions and to conserve the VWF molecules in their unstable, elongated conformation, we visualize at single molecule level by AFM that VWF is preferentially cleaved by the protease ADAMTS13 at higher shear rates. In contrast to this high shear-rate-selective behavior, VWF binds FVIII more effectively only below a critical shear rate of ∼30.000 s(-1), indicating that under harsh shear conditions FVIII is released from its carrier protein. This may be required to facilitate delivery of FVIII locally to promote secondary hemostasis.
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Affiliation(s)
- Klaus Bonazza
- Institute of Chemical Technologies and Analytics, Vienna University of Technology , Getreidemarkt 9/164, A-1060 Vienna, Austria
| | | | - Gerald Schrenk
- Baxalta Innovations, Industriestrasse 67, A-1221 Vienna, Austria
| | - Johannes Frank
- Central Machine Shop of the Faculty Technical Chemistry, Vienna University of Technology , Getreidemarkt 9/174, A-1060 Vienna, Austria
| | - Günter Allmaier
- Institute of Chemical Technologies and Analytics, Vienna University of Technology , Getreidemarkt 9/164, A-1060 Vienna, Austria
| | - Peter L Turecek
- Baxalta Innovations, Industriestrasse 67, A-1221 Vienna, Austria
| | | | - Gernot Friedbacher
- Institute of Chemical Technologies and Analytics, Vienna University of Technology , Getreidemarkt 9/164, A-1060 Vienna, Austria
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Gogia S, Lo CY, Neelamegham S. Detection of Plasma Protease Activity Using Microsphere-Cytometry Assays with E. coli Derived Substrates: VWF Proteolysis by ADAMTS13. PLoS One 2015; 10:e0126556. [PMID: 25992814 PMCID: PMC4436310 DOI: 10.1371/journal.pone.0126556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 04/03/2015] [Indexed: 11/19/2022] Open
Abstract
Protease levels in human blood are often prognostic indicators of inflammatory, thrombotic or oncogenic disorders. The measurement of such enzyme activities in substrate-based assays is complicated due to the low prevalence of these enzymes and steric hindrance of the substrates by the more abundant blood proteins. To address these limitations, we developed a molecular construct that is suitable for microsphere-cytometer based assays in the milieu of human blood plasma. In this proof of principle study, we demonstrate the utility of this substrate to measure metalloprotease ADAMTS13 activity. The substrate, expressed in E. coli as a fusion protein, contains the partial A2-domain of von Willebrand factor (VWF amino acids 1594-1670) that is mutated to include a single primary amine at the N-terminus and free cysteines at the C-terminus. N-terminus fluorescence conjugation was possible using NHS (N-hydroxysuccinimide) chemistry. Maleimide-PEG(Polyethylene glycol)n-biotin coupling at the C-terminus allowed biotinylation with variable PEG spacer lengths. Once bound to streptavidin-bearing microspheres, the substrate fluorescence signal decreased in proportion with ADAMTS13 concentration. Whereas recombinant ADAMTS13 activity could be quantified using substrates with all PEG repeat-lengths, only the construct with the longer 77 PEG-unit could quantify proteolysis in blood plasma. Using this longer substrate, plasma ADAMTS13 down to 5% of normal levels could be detected within 30 min. Such measurements could also be readily performed under conditions resembling hyperbilirubinemia. Enzyme catalytic activity was tuned by varying buffer calcium, with lower divalent ion concentrations enhancing cleavage. Overall, the study highlights the substrate design features important for the creation of efficient proteolysis assays in the setting of human plasma. In particular, it emphasizes the need to introduce PEG spacers in plasma-based experiments, a design attribute commonly ignored in immobilized peptide-substrate assays.
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Affiliation(s)
- Shobhit Gogia
- Department of Chemical and Biological Engineering and NY State Center for Excellence in Bioinformatics and Life Sciences, State University of New York, Buffalo, New York, United States of America
| | - Chi Y. Lo
- Department of Chemical and Biological Engineering and NY State Center for Excellence in Bioinformatics and Life Sciences, State University of New York, Buffalo, New York, United States of America
| | - Sriram Neelamegham
- Department of Chemical and Biological Engineering and NY State Center for Excellence in Bioinformatics and Life Sciences, State University of New York, Buffalo, New York, United States of America
- * E-mail:
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De Cock E, Hermans C, De Raeymaecker J, De Ceunynck K, De Maeyer B, Vandeputte N, Vandenbulcke A, Deckmyn H, Rottensteiner H, De Maeyer M, De Meyer SF, Vanhoorelbeke K. The novel ADAMTS13-p.D187H mutation impairs ADAMTS13 activity and secretion and contributes to thrombotic thrombocytopenic purpura in mice. J Thromb Haemost 2015; 13:283-92. [PMID: 25442981 DOI: 10.1111/jth.12804] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Indexed: 11/29/2022]
Abstract
BACKGROUND Congenital thrombotic thrombocytopenic purpura (TTP) is characterized by mutations in the ADAMTS13 gene, which either impair protein secretion or influence ADAMTS13 (A Disintegrin-like And Metalloprotease domain with ThromboSpondin type-1 motif, member 13) activity. Phenotypic consequences of these mutations have not yet been evaluated in animal models for TTP. OBJECTIVES To identify the in vitro effect of a novel ADAMTS13 mutation and to investigate whether this mutation induces TTP in vivo. METHODS All 29 ADAMTS13 exons with exon-intron boundaries of a patient with pregnancy-onset TTP were sequenced. Wild-type and mutant ADAMTS13 proteins were both transiently and stably expressed in human embryonic kidney cells, and their activity was evaluated in vitro using fluorescence resonance energy transfer and flow assays. Molecular dynamics simulations were performed to study Ca(2+) stability. Adamts13(-/-) mice were hydrodynamically injected with wild-type and mutant expression plasmids and triggered with recombinant human von Willebrand factor. RESULTS We identified a novel heterozygous c.559G>C mutation in exon 6 of the proposita's ADAMTS13 gene. This mutation resulted in a p.Asp187His substitution (p.D187H), which was located in the high affinity Ca(2+) -binding site in the metalloprotease domain of ADAMTS13. The homozygous p.D187H mutation down-regulated ADAMTS13 activity in vitro. Impaired proteolytic activity was linked to unstable Ca(2+) binding as visualized using a molecular dynamics simulation. In addition, the p.D187H mutation affects protein secretion in vitro. In Adamts13(-/-) mice, the homozygous p.D187H mutation reduced ADAMTS13 secretion and activity and contributed to TTP when these mice were triggered with recombinant human von Willebrand factor. CONCLUSIONS Our data indicate that the p.D187H mutation impairs ADAMTS13 activity and secretion and is responsible for TTP onset in mice.
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Affiliation(s)
- E De Cock
- Laboratory for Thrombosis Research, KU Leuven Kulak, Kortrijk, Belgium
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Muia J, Zhu J, Gupta G, Haberichter SL, Friedman KD, Feys HB, Deforche L, Vanhoorelbeke K, Westfield LA, Roth R, Tolia NH, Heuser JE, Sadler JE. Allosteric activation of ADAMTS13 by von Willebrand factor. Proc Natl Acad Sci U S A 2014; 111:18584-9. [PMID: 25512528 PMCID: PMC4284596 DOI: 10.1073/pnas.1413282112] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The metalloprotease ADAMTS13 cleaves von Willebrand factor (VWF) within endovascular platelet aggregates, and ADAMTS13 deficiency causes fatal microvascular thrombosis. The proximal metalloprotease (M), disintegrin-like (D), thrombospondin-1 (T), Cys-rich (C), and spacer (S) domains of ADAMTS13 recognize a cryptic site in VWF that is exposed by tensile force. Another seven T and two complement C1r/C1s, sea urchin epidermal growth factor, and bone morphogenetic protein (CUB) domains of uncertain function are C-terminal to the MDTCS domains. We find that the distal T8-CUB2 domains markedly inhibit substrate cleavage, and binding of VWF or monoclonal antibodies to distal ADAMTS13 domains relieves this autoinhibition. Small angle X-ray scattering data indicate that distal T-CUB domains interact with proximal MDTCS domains. Thus, ADAMTS13 is regulated by substrate-induced allosteric activation, which may optimize VWF cleavage under fluid shear stress in vivo. Distal domains of other ADAMTS proteases may have similar allosteric properties.
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Affiliation(s)
| | | | | | | | | | - Hendrik B Feys
- Transfusion Research Center, Belgian Red Cross-Flanders, Ghent, Belgium; and
| | - Louis Deforche
- Laboratory for Thrombosis Research, KU Leuven Kulak, 8500 Kortrijk, Belgium
| | | | | | | | - Niraj Harish Tolia
- Biochemistry and Molecular Biophysics, and Molecular Microbiology and Microbial Pathogenesis, Washington University School of Medicine, St. Louis, MO 63110
| | | | - J Evan Sadler
- Departments of Medicine, Biochemistry and Molecular Biophysics, and
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Feys HB, Van Aelst B, Devreese K, Devloo R, Coene J, Vandekerckhove P, Compernolle V. Oxygen removal during pathogen inactivation with riboflavin and UV light preserves protein function in plasma for transfusion. Vox Sang 2013; 106:307-15. [PMID: 24460692 DOI: 10.1111/vox.12106] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 09/25/2013] [Accepted: 10/01/2013] [Indexed: 01/15/2023]
Abstract
BACKGROUND AND OBJECTIVE Photochemical pathogen inactivation technologies (PCT) for individual transfusion products act by inhibition of replication through irreversibly damaging nucleic acids. Concern on the collateral impact of PCT on the blood component's integrity has caused reluctance to introduce this technology in routine practice. This work aims to uncover the mechanism of damage to plasma constituents by riboflavin pathogen reduction technology (RF-PRT). METHODS Activity and antigen of plasma components were determined following RF-PRT in the presence or absence of dissolved molecular oxygen. RESULTS Employing ADAMTS13 as a sentinel molecule in plasma, our data show that its activity and antigen are reduced by 23 ± 8% and 29 ± 9% (n = 24), respectively, which corroborates with a mean decrease of 25% observed for other coagulation factors. Western blotting of ADAMTS13 shows decreased molecular integrity, with no obvious indication of additional proteolysis nor is riboflavin able to directly inhibit the enzyme. However, physical removal of dissolved oxygen prior to RF-PRT protects ADAMTS13 as well as FVIII and fibrinogen from damage, indicating a direct role for reactive oxygen species. Redox dye measurements indicate that superoxide anions are specifically generated during RF-PRT. Protein carbonyl content as a marker of disseminated irreversible biomolecular damage was significantly increased (3·1 ± 0·8 vs. 1·6 ± 0·5 nmol/mg protein) following RF-PRT, but not in the absence of dissolved molecular oxygen (1·8 ± 0·4 nmol/mg). CONCLUSIONS RF-PRT of single plasma units generates reactive oxygen species that adversely affect biomolecular integrity of relevant plasma constituents, a side-effect, which can be bypassed by applying hypoxic conditions during the pathogen inactivation process.
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Affiliation(s)
- H B Feys
- Transfusion Research Center, Belgian Red Cross-Flanders, Ghent, Belgium
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Muia J, Gao W, Haberichter SL, Dolatshahi L, Zhu J, Westfield LA, Covill SC, Friedman KD, Sadler JE. An optimized fluorogenic ADAMTS13 assay with increased sensitivity for the investigation of patients with thrombotic thrombocytopenic purpura. J Thromb Haemost 2013; 11:1511-8. [PMID: 23773695 PMCID: PMC3807872 DOI: 10.1111/jth.12319] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2013] [Accepted: 06/06/2013] [Indexed: 01/30/2023]
Abstract
BACKGROUND Most ADAMTS13 assays use non-physiological conditions (low ionic strength, low pH, barium chloride), are subject to interference from plasma proteins, hemoglobin and bilirubin, and have limited sensitivity, especially for inhibitors. OBJECTIVES We addressed these constraints by designing a substrate that can be used in undiluted plasma. METHODS A polypeptide was expressed in E. coli that corresponds to von Willebrand factor Gln(1599) -Arg(1668) , with mutations N1610C and K1617R and an N-terminal Gly. Substrate FRETS-rVWF71 was prepared by modifying Cys(1610) with DyLight 633 (abs 638 nm, em 658 nm) and the N-terminus with IRDye QC-1 (abs 500-800 nm). Assays were performed at pH 7.4 in 150 mm NaCl, 10 mm CaCl2 . RESULTS Serum and plasma anticoagulated with citrate or heparin had equivalent ADAMTS13 activity with FRETS-rVWF71. Neither bilirubin (≤ 20 mg dL(-1) ) nor hemoglobin (≤ 20 g L(-1) ) interfered with product detection. Assays with FRETS-rVWF71 and FRETS-VWF73 gave similar results (R(2 ) = 0.95) for plasma from 80 subjects with thrombotic microangiopathy, 22 subjects with other causes of thrombocytopenia, and 20 healthy controls. The limit of detection with FRETS-rVWF71 for ADAMTS13 activity was ≤ 0.3%. Inhibitor assays with FRETS-rVWF71 gave titers ~2.5-fold higher than with FRETS-VWF73 and clearly distinguished patients with and without inhibitors. CONCLUSIONS FRETS-rVWF71 is suitable for ADAMTS13 assays in minimally diluted plasma or serum without interference from proteins, bilirubin or free hemoglobin in plasma. Optimized detection of ADAMTS13 inhibitors will facilitate the monitoring of antibody responses during the treatment of thrombotic thrombocytopenic purpura.
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Affiliation(s)
- J Muia
- Departments of Medicine, Washington University School of Medicine, St Louis, MO 63110, USA
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Akiyama M, Nakayama D, Takeda S, Kokame K, Takagi J, Miyata T. Crystal structure and enzymatic activity of an ADAMTS-13 mutant with the East Asian-specific P475S polymorphism. J Thromb Haemost 2013; 11:1399-406. [PMID: 23621748 DOI: 10.1111/jth.12279] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 04/05/2013] [Indexed: 11/29/2022]
Abstract
BACKGROUND An East Asian-specific P475S polymorphism in the gene encoding ADAMTS-13 causes an approximately 16% reduction in plasma ADAMTS-13 activity. OBJECTIVES To demonstrate the impact of this dysfunctional polymorphism by characterizing the structure and activity of the P475S mutant protein. METHODS We determined the crystal structure of the P475S mutant of ADAMTS-13-DTCS (DTCS-P475S, residues 287-685) and compared it with the wild-type structure. We determined the enzymatic parameters of ADAMTS-13-MDTCS (residues 75-685) and MDTCS-P475S, and further examined the effects of denaturants and reaction temperature on their activity. We also examined the cleavage of shear-treated von Willebrand factor (VWF) by MDTCS-P475S. RESULTS MDTCS-P475S showed a reaction rate similar to that of wild-type MDTCS, but showed two-fold lower affinity for the peptidyl substrate, indicating that the Pro475-containing V-loop (residues 474-481) in the CA domain is a substrate-binding exosite. Structural analysis showed that the conformation of the V-loop was significantly different in DTCS-P475S and the wild type, where no obvious interactions of Ser475 with other residues were observed. This explains the higher susceptibility of the enzymatic activity of MDTCS-P475S to reaction environments such as denaturants and high temperature. MDTCS-P475S can moderately cleave shear-treated VWF. CONCLUSIONS We have provided structural evidence that the P475S polymorphism in ADAMTS-13 leads to increased local structural instability, resulting in lowered affinity for the substrate without changing the reaction rate. The moderate activity of ADAMTS-13-P475S for shear-treated VWF is sufficient to prevent thrombotic thrombocytopenic purpura (TTP) onset.
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Affiliation(s)
- M Akiyama
- Department of Molecular Pathogenesis, National Cerebral and Cardiovascular Center, Osaka, Japan.
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Colace TV, Diamond SL. Direct observation of von Willebrand factor elongation and fiber formation on collagen during acute whole blood exposure to pathological flow. Arterioscler Thromb Vasc Biol 2012; 33:105-13. [PMID: 23104847 DOI: 10.1161/atvbaha.112.300522] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE In severe stenosis, von Willebrand factor (vWF) experiences millisecond exposures to pathological wall shear rates (γ(w)). We sought to evaluate the deposition of vWF onto collagen surfaces under flow in these environments. METHODS AND RESULTS Distinct from viscometry experiments that last many seconds, we deployed microfluidic devices for single-pass perfusion of whole blood or platelet-free plasma over fibrillar type 1 collagen (<50 ms transit time) at pathological γ(w) or spatial wall shear rate gradients (grad γ(w)). Using fluorescent anti-vWF, long thick vWF fibers (>20 μm) bound to collagen were visualized at constant γ(w)>30000 s(-1) during perfusion of platelet-free plasma, a process enhanced by EDTA. Rapid acceleration or deceleration of EDTA platelet-free plasma at grad γ(w)=±1.1×10(5) to ±4.3×10(7) s(-1)/cm did not promote vWF deposition. At 19400 s(-1), EDTA blood perfusion resulted in rolling vWF-platelet nets, although blood perfusion (normal Ca(2+)) generated large vWF/platelet deposits that repeatedly embolized and were blocked by anti-glycoprotein Ib or the α(IIb)β(3) inhibitor GR144053 and did not require grad γ(w). Blood perfusion at venous shear rate (200 s(-1)) produced a stable platelet deposit that was a substrate for massive but unstable vWF-platelet aggregates when flow was increased to 7800 s(-1). CONCLUSIONS Triggered by collagen and enhanced by platelet glycoprotein Ib and α(IIb)β(3), vWF fiber formation occurred during acute exposures to pathological γ(w) and did not require gradients in wall shear rate.
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Affiliation(s)
- Thomas V Colace
- Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, 1024 Vagelos Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104, USA
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De Ceunynck K, Rocha S, Feys HB, De Meyer SF, Uji-i H, Deckmyn H, Hofkens J, Vanhoorelbeke K. Local elongation of endothelial cell-anchored von Willebrand factor strings precedes ADAMTS13 protein-mediated proteolysis. J Biol Chem 2011; 286:36361-7. [PMID: 21896483 DOI: 10.1074/jbc.m111.271890] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Platelet-decorated von Willebrand factor (VWF) strings anchored to the endothelial surface are rapidly cleaved by ADAMTS13. Individual VWF string characteristics such as number, location, and auxiliary features of the ADAMTS13 cleavage sites were explored here using imaging and computing software. By following changes in VWF string length, we demonstrated that VWF strings are cleaved multiple times, successively shortening string length in the function of time and generating fragments ranging in size from 5 to over 100 μm. These are larger than generally observed in normal plasma, indicating that further proteolysis takes place in circulation. Interestingly, in 89% of all cleavage events, VWF strings elongate precisely at the cleavage site before ADAMTS13 proteolysis. These local elongations are a general characteristic of VWF strings, independent of the presence of ADAMTS13. Furthermore, large elongations, ranging in size from 1.4 to 40 μm, occur at different sites in space and time. In conclusion, ADAMTS13-mediated proteolysis of VWF strings under flow is preceded by large elongations of the string at the cleavage site. These elongations may lead to the simultaneous exposure of many exosites, thereby facilitating ADAMTS13-mediated cleavage.
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Affiliation(s)
- Karen De Ceunynck
- Laboratory for Thrombosis Research, Katholieke Universiteit Leuven Campus Kortrijk, B-8500 Kortrijk, Belgium
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Modeling ADAMTS13-von Willebrand factor interaction: Implications for oxidative stress-related cardiovascular diseases and type 2A von Willebrand disease. Biophys Chem 2011; 160:1-11. [PMID: 21937160 DOI: 10.1016/j.bpc.2011.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 07/26/2011] [Accepted: 07/27/2011] [Indexed: 01/15/2023]
Abstract
The haemostatic potential of von Willebrand factor, a glycoprotein expressed by endothelial cells as ultra-large polymers (UL-vWF)(1), increases with its length, which in turn is regulated proteolytically by ADAMTS13, a zinc-metalloprotease selectively cleaving vWF at the Tyr1605-Met1606 bond. We have recently shown that in vitro oxidation of Met1606, under conditions mimicking those found in diseases characterized by high oxidative stress, severely impairs proteolysis by ADAMTS13, with a resulting pro-thrombotic effect caused by the accumulation of UL-vWF species. Conversely, Val1607Asp mutation, found in vWF from patients with type 2A von Willebrand disease, accelerates proteolysis of vWF, with a final hemorrhagic effect. Considering the physio-pathological importance of ADAMTS13-vWF interaction and the absence of experimental structural data, here we produced by homology modeling techniques a three-dimensional model of ADAMTS13 metalloprotease domain (M13). Thereafter, the vWF(1604-1607) peptide, containing the cleavable Tyr1605-Met1606 bond, was manually docked into the protease active site and the resulting model complex provided us key information for interpreting on structural grounds the variable effects that chemical modifications/mutations in vWF have on proteolysis by ADAMTS13.
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Calcium modulates force sensing by the von Willebrand factor A2 domain. Nat Commun 2011; 2:385. [PMID: 21750539 PMCID: PMC3144584 DOI: 10.1038/ncomms1385] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Accepted: 06/09/2011] [Indexed: 11/09/2022] Open
Abstract
von Willebrand factor (VWF) multimers mediate primary adhesion and aggregation of platelets. VWF potency critically depends on multimer size, which is regulated by a feedback mechanism involving shear-induced unfolding of the VWF-A2 domain and cleavage by the metalloprotease ADAMTS-13. Here we report crystallographic and single-molecule optical tweezers data on VWF-A2 providing mechanistic insight into calcium-mediated stabilization of the native conformation that protects A2 from cleavage by ADAMTS-13. Unfolding of A2 requires higher forces when calcium is present and primarily proceeds through a mechanically stable intermediate with non-native calcium coordination. Calcium further accelerates refolding markedly, in particular, under applied load. We propose that calcium improves force sensing by allowing reversible force switching under physiologically relevant hydrodynamic conditions. Our data show for the first time the relevance of metal coordination for mechanical properties of a protein involved in mechanosensing.
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Unraveling the scissile bond: how ADAMTS13 recognizes and cleaves von Willebrand factor. Blood 2011; 118:3212-21. [PMID: 21715306 DOI: 10.1182/blood-2011-02-306597] [Citation(s) in RCA: 205] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
von Willebrand factor (VWF) is a large adhesive glycoprotein with established functions in hemostasis. It serves as a carrier for factor VIII and acts as a vascular damage sensor by attracting platelets to sites of vessel injury. VWF size is important for this latter function, with larger multimers being more hemostatically active. Functional imbalance in multimer size can variously cause microvascular thrombosis or bleeding. The regulation of VWF multimeric size and platelet-tethering function is carried out by ADAMTS13, a plasma metalloprotease that is constitutively active. Unusually, protease activity of ADAMTS13 is controlled not by natural inhibitors but by conformational changes in its substrate, which are induced when VWF is subject to elevated rheologic shear forces. This transforms VWF from a globular to an elongated protein. This conformational transformation unfolds the VWF A2 domain and reveals cryptic exosites as well as the scissile bond. To enable VWF proteolysis, ADAMTS13 makes multiple interactions that bring the protease to the substrate and position it to engage with the cleavage site as this becomes exposed by shear. This article reviews recent literature on the interaction between these 2 multidomain proteins and provides a summary model to explain proteolytic regulation of VWF by ADAMTS13.
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A novel calcium-binding site of von Willebrand factor A2 domain regulates its cleavage by ADAMTS13. Blood 2011; 117:4623-31. [PMID: 21385852 DOI: 10.1182/blood-2010-11-321596] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
The proteolysis of VWF by ADAMTS13 is an essential step in the regulation of its hemostatic and thrombogenic potential. The cleavage occurs at strand β4 in the structural core of the A2 domain of VWF, so unfolding of the A2 domain is a prerequisite for cleavage. In the present study, we present the crystal structure of an engineered A2 domain that exhibits a significant difference in the α3-β4 loop compared with the previously reported structure of wild-type A2. Intriguingly, a metal ion was detected at a site formed mainly by the C-terminal region of the α3-β4 loop that was later identified as Ca(²+) after various biophysical and biochemical studies. Force-probe molecular dynamic simulations of a modeled structure of the wild-type A2 featuring the discovered Ca(²+)-binding site revealed that an increase in force was needed to unfold strand β4 when Ca(²+) was bound. Cleavage assays consistently demonstrated that Ca(²+) binding stabilized the A2 domain and impeded its unfolding, and consequently protected it from cleavage by ADAMTS13. We have revealed a novel Ca(²+)-binding site at the A2 domain of VWF and demonstrated a relationship between Ca(²+) and force in the regulation of VWF and primary hemostasis.
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Han Y, Xiao J, Falls E, Zheng XL. A shear-based assay for assessing plasma ADAMTS13 activity and inhibitors in patients with thrombotic thrombocytopenic purpura. Transfusion 2011; 51:1580-91. [PMID: 21251003 DOI: 10.1111/j.1537-2995.2010.03020.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Severe deficiency of plasma ADAMTS13 activity is a frequent finding in patients with hereditary and acquired thrombotic thrombocytopenic purpura (TTP). To date, plasma ADAMTS13 activity is determined by cleavage of either predenatured von Willebrand factor (VWF) or small peptides derived from the VWF-A2 domain. The physiologic relevance of the assay results is uncertain. STUDY DESIGN AND METHODS We sought to develop a novel shear-based assay to assess plasma ADAMTS13 activity and inhibitors. We also compared this assay with a fluorogenic peptide assay. RESULTS We found that an incubation of purified plasma VWF with 0.5 to 1.0 µL of citrated plasma under constant vortexing at 2500 rpm for 60 minutes in the presence of 5 mmol/L CaCl(2) and 1.7 µmol/L ZnCl(2) and low concentration of NaCl resulted in the maximal cleavage of VWF. The cleavage product could be separated by a 2.5% agarose gel and detected by Western blotting. The assay revealed that plasma and recombinant ADAMTS13 are highly sensitive to inhibition by zinc and chloride ions. Under the optimal conditions, the shear-based assay appeared to be more sensitive than the guanidine-denaturization assay for determining plasma ADAMTS13 activity. CONCLUSIONS Our fluid shear-based assay may be useful for investigating basic biologic function and regulation of ADAMTS13 metalloprotease. It may also be applicable for assessing plasma ADAMTS13 activity and inhibitors in TTP patients.
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Affiliation(s)
- Yue Han
- Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia and The University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104, USA
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42
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Dayananda KM, Gogia S, Neelamegham S. Escherichia coli-derived von Willebrand factor-A2 domain fluorescence/Förster resonance energy transfer proteins that quantify ADAMTS13 activity. Anal Biochem 2010; 410:206-13. [PMID: 21146487 DOI: 10.1016/j.ab.2010.12.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 11/24/2010] [Accepted: 12/06/2010] [Indexed: 10/18/2022]
Abstract
The cleavage of the A2 domain of von Willebrand factor (VWF) by the metalloprotease ADAMTS13 regulates VWF size and platelet thrombosis rates. Reduction or inhibition of this enzyme activity leads to thrombotic thrombocytopenic purpura (TTP). We generated a set of novel molecules called VWF-A2 FRET (fluorescence/Förster resonance energy transfer) proteins, where variants of yellow fluorescent protein (Venus) and cyan fluorescent protein (Cerulean) flank either the entire VWF-A2 domain (175 amino acids) or truncated fragments (141, 113, and 77 amino acids) of this domain. These proteins were expressed in Escherichia coli in soluble form, and they exhibited FRET properties. Results show that the introduction of Venus/Cerulean itself did not alter the ability of VWF-A2 to undergo ADAMTS13-mediated cleavage. The smallest FRET protein, XS-VWF, detected plasma ADAMTS13 activity down to 10% of normal levels. Tests of acquired and inherited TTP could be completed within 30 min. VWF-A2 conformation changed progressively, and not abruptly, on increasing urea concentrations. Although proteins with 77 and 113 VWF-A2 residues were cleaved in the absence of denaturant, 4M urea was required for the efficient cleavage of larger constructs. Overall, VWF-A2 FRET proteins can be applied both for the rapid diagnosis of plasma ADAMTS13 activity and as a tool to study VWF-A2 conformation dynamics.
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Affiliation(s)
- Kannayakanahalli M Dayananda
- Department of Chemical and Biological Engineering, State University of New York at Buffalo, Buffalo, NY 14260, USA
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Thrombotic thrombocytopenic purpura directly linked with ADAMTS13 inhibition in the baboon (Papio ursinus). Blood 2010; 116:2005-10. [DOI: 10.1182/blood-2010-04-280479] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Abstract
Thrombotic thrombocytopenic purpura (TTP) is the prototypical microangiopathy characterized by disseminated microthromboses, hemolytic anemia, and ultimately organ dysfunction. A link with deficiency of the von Willebrand factor–cleaving protease (ADAMTS13) has been demonstrated, but additional genetic and/or environmental triggers are thought to be required to incite acute illness. Here we report that 4 days of ADAMTS13 functional inhibition is sufficient to induce TTP in the baboon (Papio ursinus), in the absence of inciting triggers because injections with an inhibitory monoclonal antibody (mAb) consistently (n = 6) induced severe thrombocytopenia (< 12 × 109/L), microangiopathic hemolytic anemia, and a rapid rise in serum lactate dehydrogenase. Immunohistochemical staining revealed the characteristic disseminated platelet- and von Willebrand factor–rich thrombi in kidney, heart, brain, and spleen but not lungs. Prolonged inhibition (14 days, n = 1) caused myocardial ischemic damage and asplenia but not death. Control animals (n = 5) receiving equal doses of a noninhibitory anti-ADAMTS13 mAb remained unaffected. Our results provide evidence for a direct link between TTP and ADAMTS13 inhibition and for a mild disease onset. Furthermore, we present a reliable animal model of this disease as an opportunity for the development and validation of novel treatment strategies.
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Feys HB, Vandeputte N, Palla R, Peyvandi F, Peerlinck K, Deckmyn H, Lijnen HR, Vanhoorelbeke K. Inactivation of ADAMTS13 by plasmin as a potential cause of thrombotic thrombocytopenic purpura. J Thromb Haemost 2010; 8:2053-62. [PMID: 20553378 DOI: 10.1111/j.1538-7836.2010.03942.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND ADAMTS13 deficiency causes accumulation of unusually large von Willebrand factor molecules, which cross-link platelets in the circulation or on the endothelial surface. This process of intravascular agglutination leads to the microangiopathy thrombotic thrombocytopenic purpura (TTP). Most TTP patients have acquired anti-ADAMTS13 autoantibodies that inhibit enzyme function and/or clear it from the circulation. However, the reason for ADAMTS13 deficiency is not always easily identified in a subset of patients. OBJECTIVES To determine the origin of ADAMTS13 deficiency in a case of acquired TTP. METHODS Western blotting of ADAMTS13 in plasmas from acute and remission phases was used. RESULTS The ADAMTS13 deficiency was not caused by mutations or (detectable) autoantibodies; however, an abnormal ADAMTS13 truncated fragment (100 kDa) was found in acute-phase but not remission-phase plasma. This fragment resulted from enzymatic proteolysis, as recombinant ADAMTS13 was also cleaved when in the presence of acute-phase but not remission-phase plasma. Inhibitor screening showed that ADAMTS13 was cleaved by a serine protease that could be dose-dependently inhibited by addition of exogenous α₂ -antiplasmin. Examination of the endogenous α₂-antiplasmin antigen and activity confirmed deficiency of α₂ -antiplasmin function in acute-phase but not remission-phase plasma. To investigate the possibility of ADAMTS13 cleavage by plasmin in plasma, urokinase-type plasminogen activator was added to an (unrelated) congenital α₂ -antiplasmin-deficient plasma sample to activate plasminogen. This experiment confirmed cleavage of endogenous ADAMTS13 similar to that observed in our TTP patient. CONCLUSION We report the first acquired TTP patient with cleaved ADAMTS13 and show that plasmin is involved.
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Affiliation(s)
- H B Feys
- Laboratory for Thrombosis Research, Katholieke Universiteit Leuven Campus Kortrijk, Kortrijk, Belgium
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Ying J, Ling Y, Westfield LA, Sadler JE, Shao JY. Unfolding the A2 domain of von Willebrand factor with the optical trap. Biophys J 2010; 98:1685-93. [PMID: 20409490 DOI: 10.1016/j.bpj.2009.12.4324] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 12/16/2009] [Accepted: 12/30/2009] [Indexed: 11/17/2022] Open
Abstract
Von Willebrand factor (VWF) is a multimeric plasma glycoprotein involved in both hemostasis and thrombosis. VWF conformational changes, especially unfolding of the A2 domain, may be required for efficient enzymatic cleavage in vivo. It has been shown that a single A2 domain unfolds at most probable unfolding forces of 7-14 pN at force loading rates of 0.35-350 pN/s and A2 unfolding facilitates A2 cleavage in vitro. However, it remains unknown how much force is required to unfold the A2 domain in the context of a VWF multimer where A2 may be stabilized by other domains like A1 and A3. With the optical trap, we stretched VWF multimers and a poly-protein (A1A2A3)3 that contains three repeats of the triplet A1A2A3 domains at constant speeds of 2000 nm/s and 400 nm/s, respectively, which yielded corresponding average force loading rates of 90 and 22 pN/s. We found that VWF multimers became stiffer when they were stretched and extended by force. After force increased to a certain level, sudden extensional jumps that signify domain unfolding were often observed. Histograms of the unfolding force and the unfolded contour length showed two or three peaks that were integral multiples of approximately 21 pN and approximately 63 nm, respectively. Stretching of (A1A2A3)3 yielded comparable distributions of unfolding force and unfolded contour length, showing that unfolding of the A2 domain accounts for the behavior of VWF multimers under tension. These results show that the A2 domain can be indeed unfolded in the presence of A1, A3, and other domains. Compared with the value in the literature, the larger most probable unfolding force measured in this study suggests that the A2 domain is mechanically stabilized by A1 or A3 although variations in experimental setups and conditions may complicate this interpretation.
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Affiliation(s)
- Junyi Ying
- Department of Biomedical Engineering, Washington University, St. Louis, Missouri, USA
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Skipwith CG, Cao W, Zheng XL. Factor VIII and platelets synergistically accelerate cleavage of von Willebrand factor by ADAMTS13 under fluid shear stress. J Biol Chem 2010; 285:28596-603. [PMID: 20605782 DOI: 10.1074/jbc.m110.131227] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies have demonstrated that factor VIII (FVIII) or platelets alone increase cleavage of von Willebrand factor (VWF) by ADAMTS13 under mechanically induced shear stresses. We show in this study that the combination of FVIII and platelets at the physiological concentrations is more effective than either one alone. In the absence of FVIII, lyophilized platelets increase the formation of cleavage product by 2-3-fold. However, in the presence of physiological concentration of FVIII (1 nm), the formation of VWF cleavage product increases dramatically as a function of increasing platelets with the maximal rate enhancement of approximately 8-fold. Conversely, in the presence of a physiological concentration of lyophilized platelets (150 x 10(3)/microl), the half-maximal concentration of FVIII required to accelerate VWF proteolysis by ADAMTS13 reduces by approximately 10-fold (to approximately 0.3 nm) compared with that in the absence of platelets ( approximately 3.0 nm). Further studies using the FVIII derivative that lacks an acidic region (a3), an antiplatelet glycoprotein 1balpha IgG, and a purified recombinant VWF-A1 domain or glycoprotein 1balpha-stripped platelets demonstrate that the synergistic rate-enhancing effect of FVIII and platelets depends on their specific binding interactions with VWF. Our findings suggest that FVIII and platelets are cofactors that regulate proteolysis of multimeric VWF by ADAMTS13 under physiological conditions.
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Affiliation(s)
- Christopher G Skipwith
- Biochemistry and Molecular Biophysics Graduate Program, Children's Hospital of Philadelphia and the University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104, USA
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Feys HB, Anderson PJ, Vanhoorelbeke K, Majerus EM, Sadler JE. Multi-step binding of ADAMTS-13 to von Willebrand factor. J Thromb Haemost 2009; 7:2088-95. [PMID: 19765212 PMCID: PMC3863616 DOI: 10.1111/j.1538-7836.2009.03620.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND ADAMTS-13 proteolytic activity is controlled by the conformation of its substrate, von Willebrand factor (VWF), and changes in the secondary structure of VWF are essential for efficient cleavage. Substrate recognition is mediated through several non-catalytic domains in ADAMTS-13 distant from the active site. OBJECTIVES We hypothesized that not all binding sites for ADAMTS-13 in VWF are cryptic and analyzed binding of native VWF to ADAMTS-13. METHODS Immunoprecipiation of VWF-ADAMTS-13 complexes using anti-VWF antibodies and magnetic beads was used. Binding was assessed by Western blotting and immunosorbent assays. RESULTS Co-immunoprecipitation demonstrated that ADAMTS-13 binds to native multimeric VWF (K(d) of 79 +/- 11 nmol L(-1)) with no measurable proteolysis. Upon shear-induced unfolding of VWF, binding increased 3-fold and VWF was cleaved. Binding to native VWF was saturable, time dependent, reversible and did not vary with ionic strength (I of 50-200). Moreover, results with ADAMTS-13 deletion mutants indicated that binding to native VWF is mediated through domains distal to the ADAMTS-13 spacer, probably thrombospondin-1 repeats. Interestingly, this interaction occurs in normal human plasma with an ADAMTS-13 to VWF stoichiometry of 0.0040 +/- 0.0004 (mean +/- SEM, n = 10). CONCLUSIONS ADAMTS-13 binds to circulating VWF and may therefore be incorporated into a platelet-rich thrombus, where it can immediately cleave VWF that is unfolded by fluid shear stress.
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Affiliation(s)
- H B Feys
- Department of Biochemistry and Molecular Biophysics, Department of Medicine, Washington University, School of Medicine, St Louis, MO, USA
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Mutation of the H-bond acceptor S119 in the ADAMTS13 metalloprotease domain reduces secretion and substrate turnover in a patient with congenital thrombotic thrombocytopenic purpura. Blood 2009; 114:4749-52. [PMID: 19786614 DOI: 10.1182/blood-2009-07-230615] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hereditary thrombotic thrombocytopenic purpura is caused by mutations in a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS13) resulting in defective processing of von Willebrand factor (VWF) that causes intravascular platelet aggregation culminating in thrombocytopenia with shistocytic anemia. In this study the functional and structural role of a recently identified ADAMTS13 metalloprotease domain mutation S119F was investigated. Secretion from heterologous cells was hampered but not completely eliminated. Secreted S119F was active toward multimeric VWF and FRETS-VWF73 but with abnormal kinetics, having a significantly reduced overall catalytic rate (k(cat); 0.88 +/- 0.04 s(-1) vs 2.78 +/- 0.11 s(-1)) and slightly smaller Michaelis constant (K(M); 1.4 +/- 0.2microM vs 2.3 +/- 0.3microM). A computational model of the metalloprotease domain demonstrates both steric and polar interaction effects caused by S119F. Interestingly, mutant S119A has properties similar to S119F (k(cat) = 0.82 +/- 0.03 s(-1) and K(M) = 1.1 +/- 0.1microM), allowing to assign distorted kinetics to the loss of the H-bond with conserved residue W262. We conclude that the S119-W262 H-bond is crucial for maximal turnover.
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Abstract
ADAMTS13 regulates the multimeric size of von Willebrand factor (VWF). Its function is highly dependent upon Ca(2+) ions. Using the initial rates of substrate (VWF115, VWF residues 1554-1668) proteolysis by ADAMTS13 preincubated with varying Ca(2+) concentrations, a high-affinity functional ADAMTS13 Ca(2+)-binding site was suggested with K(D(app)) of 80 muM (+/- 15 muM) corroborating a previously reported study. When Glu83 or Asp173 (residues involved in a predicted Ca(2+)-binding site in the ADAMTS13 metalloprotease domain) were mutated to alanine, Ca(2+) dependence of proteolysis of the substrate was unaffected. Consequently, we sought and identified a candidate Ca(2+)-binding site in proximity to the ADAMTS13 active site, potentially comprising Glu184, Asp187, and Glu212. Mutagenesis of these residues within this site to alanine dramatically attenuated the K(D(app)) for Ca(2+) of ADAMTS13, and for D187A and E212A also reduced the V(max) to approximately 25% of normal. Kinetic analysis of the Asp187 mutant in the presence of excess Ca(2+) revealed an approximately 13-fold reduction in specificity constant, k(cat)/K(m), contributed by changes in both K(m) and k(cat). These results were corroborated using plasma-purified VWF as a substrate. Together, our results demonstrate that a major influence of Ca(2+) upon ADAMTS13 function is mediated through binding to a high-affinity site adjacent to its active site cleft.
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Extensive contacts between ADAMTS13 exosites and von Willebrand factor domain A2 contribute to substrate specificity. Blood 2008; 112:1713-9. [PMID: 18492952 DOI: 10.1182/blood-2008-04-148759] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The metalloprotease ADAMTS13 efficiently cleaves only the Tyr(1605)-Met(1606) bond in the central A2 domain of multimeric von Willebrand factor (VWF), even though VWF constitutes only 0.02% of plasma proteins. This remarkable specificity depends in part on binding of the noncatalytic ADAMTS13 spacer domain to the C-terminal alpha-helix of VWF domain A2. By kinetic analysis of recombinant ADAMTS13 constructs, we show that the first thrombospondin-1, Cys-rich, and spacer domains of ADAMTS13 interact with segments of VWF domain A2 between Gln(1624) and Arg(1668), and together these exosite interactions increase the rate of substrate cleavage by at least approximately 300-fold. Internal deletion of Gln(1624)-Arg(1641) minimally affected the rate of cleavage, indicating that ADAMTS13 does not require a specific distance between the scissile bond and auxiliary substrate binding sites. Smaller deletions of the P2-P9 or the P4'-P18' residues on either side of the Tyr(1605)-Met(1606) bond abolished cleavage, indicating that the metalloprotease domain interacts with additional residues flanking the cleavage site. Thus, specific recognition of VWF depends on cooperative, modular contacts between several ADAMTS13 domains and discrete segments of VWF domain A2.
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