1
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Herrera-Rodríguez AM, Dasanna AK, Daday C, Cruz-Chú ER, Aponte-Santamaría C, Schwarz US, Gräter F. The role of flow in the self-assembly of dragline spider silk proteins. Biophys J 2023; 122:4241-4253. [PMID: 37803828 PMCID: PMC10645567 DOI: 10.1016/j.bpj.2023.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 07/14/2023] [Accepted: 09/29/2023] [Indexed: 10/08/2023] Open
Abstract
Hydrodynamic flow in the spider duct induces conformational changes in dragline spider silk proteins (spidroins) and drives their assembly, but the underlying physical mechanisms are still elusive. Here we address this challenging multiscale problem with a complementary strategy of atomistic and coarse-grained molecular dynamics simulations with uniform flow. The conformational changes at the molecular level were analyzed for single-tethered spider silk peptides. Uniform flow leads to coiled-to-stretch transitions and pushes alanine residues into β sheet and poly-proline II conformations. Coarse-grained simulations of the assembly process of multiple semi-flexible block copolymers using multi-particle collision dynamics reveal that the spidroins aggregate faster but into low-order assemblies when they are less extended. At medium-to-large peptide extensions (50%-80%), assembly slows down and becomes reversible with frequent association and dissociation events, whereas spidroin alignment increases and alanine repeats form ordered regions. Our work highlights the role of flow in guiding silk self-assembly into tough fibers by enhancing alignment and kinetic reversibility, a mechanism likely relevant also for other proteins whose function depends on hydrodynamic flow.
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Affiliation(s)
| | - Anil Kumar Dasanna
- BioQuant, Heidelberg University, Heidelberg, Germany; Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany
| | - Csaba Daday
- Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Eduardo R Cruz-Chú
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Ulrich S Schwarz
- BioQuant, Heidelberg University, Heidelberg, Germany; Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany.
| | - Frauke Gräter
- Heidelberg Institute for Theoretical Studies, Heidelberg, Germany; Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg, Germany.
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2
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Wang H, Li D, Chen Y, Liu Z, Liu Y, Meng X, Fan H, Hou S. Shear-induced acquired von Willebrand syndrome: an accomplice of bleeding events in adults on extracorporeal membrane oxygenation support. Front Cardiovasc Med 2023; 10:1159894. [PMID: 37485275 PMCID: PMC10357042 DOI: 10.3389/fcvm.2023.1159894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/21/2023] [Indexed: 07/25/2023] Open
Abstract
Extracorporeal membrane oxygenation (ECMO) is an increasingly acceptable life-saving mechanical assistance system that provides cardiac and/or respiratory support for several reversible or treatable diseases. Despite important advances in technology and clinical management, bleeding remains a significant and common complication associated with increased morbidity and mortality. Some studies suggest that acquired von Willebrand syndrome (AVWS) is one of the etiologies of bleeding. It is caused by shear-induced deficiency of von Willebrand factor (VWF). VWF is an important glycoprotein for hemostasis that acts as a linker at sites of vascular injury for platelet adhesion and aggregation under high shear stress. AVWS can usually be diagnosed within 24 h after initiation of ECMO and is always reversible after explantation. Nonetheless, the main mechanism for the defect in the VWF multimers under ECMO support and the association between AVWS and bleeding complications remains unknown. In this review, we specifically discuss the loss of VWF caused by shear induction in the context of ECMO support as well as the current diagnostic and management strategies for AVWS.
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Affiliation(s)
- Haiwang Wang
- Institute of Disaster and Emergency Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Disaster Medicine Technology, Tianjin University, Tianjin, China
- Wenzhou Safety (Emergency) Institute, Tianjin University, Wenzhou, China
| | - Duo Li
- Institute of Disaster and Emergency Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Disaster Medicine Technology, Tianjin University, Tianjin, China
- Wenzhou Safety (Emergency) Institute, Tianjin University, Wenzhou, China
| | - Yuansen Chen
- Institute of Disaster and Emergency Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Disaster Medicine Technology, Tianjin University, Tianjin, China
- Wenzhou Safety (Emergency) Institute, Tianjin University, Wenzhou, China
| | - Ziquan Liu
- Institute of Disaster and Emergency Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Disaster Medicine Technology, Tianjin University, Tianjin, China
- Wenzhou Safety (Emergency) Institute, Tianjin University, Wenzhou, China
| | - Yanqing Liu
- Institute of Disaster and Emergency Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Disaster Medicine Technology, Tianjin University, Tianjin, China
- Wenzhou Safety (Emergency) Institute, Tianjin University, Wenzhou, China
| | - Xiangyan Meng
- Institute of Disaster and Emergency Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Disaster Medicine Technology, Tianjin University, Tianjin, China
- Wenzhou Safety (Emergency) Institute, Tianjin University, Wenzhou, China
| | - Haojun Fan
- Institute of Disaster and Emergency Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Disaster Medicine Technology, Tianjin University, Tianjin, China
- Wenzhou Safety (Emergency) Institute, Tianjin University, Wenzhou, China
| | - Shike Hou
- Institute of Disaster and Emergency Medicine, Tianjin University, Tianjin, China
- Tianjin Key Laboratory of Disaster Medicine Technology, Tianjin University, Tianjin, China
- Wenzhou Safety (Emergency) Institute, Tianjin University, Wenzhou, China
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3
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Csányi MC, Salamon P, Feller T, Bozó T, Hársfalvi J, Kellermayer MSZ. Structural hierarchy of mechanical extensibility in human von Willebrand factor multimers. Protein Sci 2023; 32:e4535. [PMID: 36478480 PMCID: PMC9798247 DOI: 10.1002/pro.4535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/04/2022] [Accepted: 12/03/2022] [Indexed: 12/13/2022]
Abstract
The von Willebrand factor (VWF) is a multimeric glycoprotein composed of 80- to 120-nm-long protomeric units and plays a fundamental role in mediating platelet function at high shear. The exact nature of the shear-induced structural transitions have remained elusive; uncovering them requires the high-resolution quantitative analysis of gradually extended VWF. Here, we stretched human blood-plasma-derived VWF with molecular combing and analyzed the axial structure of the elongated multimers with atomic force microscopy. Protomers extended through structural intermediates that could be grouped into seven distinct topographical classes. Protomer extension thus progresses through the uncoiling of the C1-6 domain segment, rearrangements among the N-terminal VWF domains, and unfolding and elastic extension of the A2 domain. The least and most extended protomer conformations were localized at the ends and the middle of the multimer, respectively, revealing an apparent necking phenomenon characteristic of plastic-material behavior. The structural hierarchy uncovered here is likely to provide a spatial control mechanism to the complex functions of VWF.
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Affiliation(s)
- Mária Csilla Csányi
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary
| | - Pál Salamon
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary,Present address:
Department of BioengineeringSapientia Hungarian University of TransylvaniaMiercurea CiucRomania
| | - Tímea Feller
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary,Present address:
Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic MedicineUniversity of LeedsLeedsUK
| | - Tamás Bozó
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary
| | - Jolán Hársfalvi
- Department of Biophysics and Radiation BiologySemmelweis UniversityBudapestHungary
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4
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Goult BT, von Essen M, Hytönen VP. The mechanical cell - the role of force dependencies in synchronising protein interaction networks. J Cell Sci 2022; 135:283155. [PMID: 36398718 PMCID: PMC9845749 DOI: 10.1242/jcs.259769] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The role of mechanical signals in the proper functioning of organisms is increasingly recognised, and every cell senses physical forces and responds to them. These forces are generated both from outside the cell or via the sophisticated force-generation machinery of the cell, the cytoskeleton. All regions of the cell are connected via mechanical linkages, enabling the whole cell to function as a mechanical system. In this Review, we define some of the key concepts of how this machinery functions, highlighting the critical requirement for mechanosensory proteins, and conceptualise the coupling of mechanical linkages to mechanochemical switches that enables forces to be converted into biological signals. These mechanical couplings provide a mechanism for how mechanical crosstalk might coordinate the entire cell, its neighbours, extending into whole collections of cells, in tissues and in organs, and ultimately in the coordination and operation of entire organisms. Consequently, many diseases manifest through defects in this machinery, which we map onto schematics of the mechanical linkages within a cell. This mapping approach paves the way for the identification of additional linkages between mechanosignalling pathways and so might identify treatments for diseases, where mechanical connections are affected by mutations or where individual force-regulated components are defective.
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Affiliation(s)
- Benjamin T. Goult
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, Kent, UK,Authors for correspondence (; )
| | - Magdaléna von Essen
- Faculty of Medicine and Health Technology, Tampere University, FI-33100 Tampere, Finland
| | - Vesa P. Hytönen
- Faculty of Medicine and Health Technology, Tampere University, FI-33100 Tampere, Finland,Fimlab Laboratories, FI-33520 Tampere, Finland,Authors for correspondence (; )
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5
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Khedr A, Mahmoud EE, Attallah N, Mir M, Boike S, Rauf I, Jama AB, Mushtaq H, Surani S, Khan SA. Role of octreotide in small bowel bleeding. World J Clin Cases 2022; 10:9192-9206. [PMID: 36159407 PMCID: PMC9477697 DOI: 10.12998/wjcc.v10.i26.9192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 07/30/2022] [Accepted: 08/15/2022] [Indexed: 02/05/2023] Open
Abstract
Gastrointestinal bleeding accounts for a drastic negative impact on the quality of the patients’ lives as it requires multiple diagnostic and therapeutic interventions to identify the source of the bleeding. Small bowel bleeding is the least common cause of gastrointestinal bleeding. However, it is responsible for the majority of complaints from patients with persisting or recurring bleeding where the primary source of bleeding cannot be identified despite investigation. A somatostatin analog known as octreotide is among the medical treatment modalities currently used to manage small bowel bleeding. This medication helps control symptoms of gastrointestinal bleeding by augmenting platelet aggregation, decreasing splanchnic blood flow, and antagonizing angiogenesis. In this review article, we will highlight the clinical efficacy of octreotide in small bowel bleeding and its subsequent effect on morbidity and mortality.
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Affiliation(s)
- Anwar Khedr
- Department of Internal Medicine, BronxCare Health System, Bronx, NY 10457, United States
| | | | - Noura Attallah
- Critical Care Medicine, Mayo Clinic Health System, Mankato, MN 56001, United States
| | - Mikael Mir
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, United States
| | - Sydney Boike
- Department of Medicine, University of Minnesota, Minneapolis, MN 55455, United States
| | - Ibtisam Rauf
- Department of Medicine, St. George School of Medicine, Grenada, West Indies
| | - Abbas B Jama
- Critical Care Medicine, Mayo Clinic Health System, Mankato, MN 56001, United States
| | - Hisham Mushtaq
- Critical Care Medicine, Mayo Clinic Health System, Mankato, MN 56001, United States
| | - Salim Surani
- Department of Medicine, Texas A&M University Health Science Center, Bryan, TX 77807, United States
| | - Syed A Khan
- Critical Care Medicine, Mayo Clinic Health System, Mankato, MN 56001, United States
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6
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Sandoval‐Pérez A, Mejía‐Restrepo V, Aponte‐Santamaría C. Thermodynamic stabilization of von Willebrand factor
A1
domain induces protein loss of function. Proteins 2022; 90:2058-2066. [DOI: 10.1002/prot.26397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 06/24/2022] [Accepted: 06/30/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Angélica Sandoval‐Pérez
- Max Planck Tandem Group in Computational Biophysics Universidad de Los Andes Bogotá Colombia
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7
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Kalbhenn J, Zieger B. Bleeding During Veno-Venous ECMO: Prevention and Treatment. Front Med (Lausanne) 2022; 9:879579. [PMID: 35677828 PMCID: PMC9168900 DOI: 10.3389/fmed.2022.879579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 04/27/2022] [Indexed: 11/26/2022] Open
Abstract
Veno-venous extracorporeal membrane oxygenation (vvECMO) has become a routine treatment for severe lung failure in specialized centers. Spontaneous bleeding complications, however, are observed in 30–60% of patients during vvECMO treatment. Bleeding increases mortality by factors 2–3. Anticoagulation in combination with several acquired bleeding disorders caused by the mechanical pump and the foreign layer of the extracorporeal system contribute to the risk of bleeding. In this review, the mechanisms of the underlying pathologies and the route from diagnosis to treatment are described.
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Affiliation(s)
- Johannes Kalbhenn
- Department of Anesthesiology and Critical Care, Faculty of Medicine, Medical Center—University of Freiburg, Freiburg im Breisgau, Germany
- *Correspondence: Johannes Kalbhenn ; orcid.org/0000-0001-7551-5082
| | - Barbara Zieger
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Faculty of Medicine, Medical Center—University of Freiburg, Freiburg im Breisgau, Germany
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8
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Tiede A, Zieger B, Lisman T. Acquired bleeding disorders. Haemophilia 2022; 28 Suppl 4:68-76. [PMID: 35521729 DOI: 10.1111/hae.14548] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/23/2020] [Indexed: 12/19/2022]
Abstract
Acquired bleeding disorders can accompany hematological, neoplastic, autoimmune, cardiovascular or liver diseases, but can sometimes also arise spontaneously. They can manifest as single factor deficiencies or as complex hemostatic abnormalities. This review addresses (a) acquired hemophilia A, an autoimmune disorder characterized by inhibitory autoantibodies against coagulation factor VIII; (b) acquired von Willebrand syndrome in patients with cardiovascular disorders, where shear stress abnormalities result in destruction of von Willebrand factor; and (c) liver function disorders that comprise complex changes in pro- and anti-hemostatic factors, whose clinical implications are often difficult to predict. The article provides an overview on the pathophysiology, diagnostic tests and state-of-the-art treatment strategies.
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Affiliation(s)
- Andreas Tiede
- Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
| | - Barbara Zieger
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ton Lisman
- Surgical Research Laboratory and Section of Hepatobiliary Surgery and Liver Transplantation, Department of Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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9
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(Physiology of Continuous-flow Left Ventricular Assist Device Therapy. Translation of the document prepared by the Czech Society of Cardiology). COR ET VASA 2022. [DOI: 10.33678/cor.2022.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Languin-Cattoën O, Laborie E, Yurkova DO, Melchionna S, Derreumaux P, Belyaev AV, Sterpone F. Exposure of Von Willebrand Factor Cleavage Site in A1A2A3-Fragment under Extreme Hydrodynamic Shear. Polymers (Basel) 2021; 13:polym13223912. [PMID: 34833213 PMCID: PMC8625202 DOI: 10.3390/polym13223912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 12/22/2022] Open
Abstract
Von Willebrand Factor (vWf) is a giant multimeric extracellular blood plasma involved in hemostasis. In this work we present multi-scale simulations of its three-domains fragment A1A2A3. These three domains are essential for the functional regulation of vWf. Namely the A2 domain hosts the site where the protease ADAMTS13 cleavages the multimeric vWf allowing for its length control that prevents thrombotic conditions. The exposure of the cleavage site follows the elongation/unfolding of the domain that is caused by an increased shear stress in blood. By deploying Lattice Boltzmann molecular dynamics simulations based on the OPEP coarse-grained model for proteins, we investigated at molecular level the unfolding of the A2 domain under the action of a perturbing shear flow. We described the structural steps of this unfolding that mainly concerns the β-strand structures of the domain, and we compared the process occurring under shear with that produced by the action of a directional pulling force, a typical condition of single molecule experiments. We observe, that under the action of shear flow, the competition among the elongational and rotational components of the fluid field leads to a complex behaviour of the domain, where elongated structures can be followed by partially collapsed melted globule structures with a very different degree of exposure of the cleavage site. Our simulations pose the base for the development of a multi-scale in-silico description of vWf dynamics and functionality in physiological conditions, including high resolution details for molecular relevant events, e.g., the binding to platelets and collagen during coagulation or thrombosis.
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Affiliation(s)
- Olivier Languin-Cattoën
- Laboratoire de Biochimie Théorique, CNRS, Université de Paris, UPR 9080, 13 rue Pierre et Marie Curie, F-75005 Paris, France; (O.L.-C.); (E.L.); (P.D.)
| | - Emeline Laborie
- Laboratoire de Biochimie Théorique, CNRS, Université de Paris, UPR 9080, 13 rue Pierre et Marie Curie, F-75005 Paris, France; (O.L.-C.); (E.L.); (P.D.)
| | - Daria O. Yurkova
- Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia;
| | - Simone Melchionna
- Dipartimento di Fisica, Università Sapienza, P.le A. Moro 5, 00185 Rome, Italy;
| | - Philippe Derreumaux
- Laboratoire de Biochimie Théorique, CNRS, Université de Paris, UPR 9080, 13 rue Pierre et Marie Curie, F-75005 Paris, France; (O.L.-C.); (E.L.); (P.D.)
| | - Aleksey V. Belyaev
- Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russia;
- Correspondence: (A.V.B.); (F.S.)
| | - Fabio Sterpone
- Laboratoire de Biochimie Théorique, CNRS, Université de Paris, UPR 9080, 13 rue Pierre et Marie Curie, F-75005 Paris, France; (O.L.-C.); (E.L.); (P.D.)
- Correspondence: (A.V.B.); (F.S.)
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11
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Evans SE, Harrington T, Rodriguez Rivero MC, Rognin E, Tuladhar T, Daly R. 2D and 3D inkjet printing of biopharmaceuticals - A review of trends and future perspectives in research and manufacturing. Int J Pharm 2021; 599:120443. [PMID: 33675921 DOI: 10.1016/j.ijpharm.2021.120443] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 12/13/2022]
Abstract
There is an ongoing global shift in pharmaceutical business models from small molecule drugs to biologics. This increase in complexity is in response to advancements in our diagnoses and understanding of diseases. With the more targeted approach coupled with its inherently more costly development and manufacturing, 2D and 3D printing are being explored as suitable techniques to deliver more personalised and affordable routes to drug discovery and manufacturing. In this review, we explore first the business context underlying this shift to biopharmaceuticals and provide an update on the latest work exploring discovery and pharmaceutics. We then draw on multiple disciplines to help reveal the shared challenges facing researchers and firms aiming to develop biopharmaceuticals, specifically when using the most commonly explored manufacturing routes of drop-on-demand inkjet printing and pneumatic extrusion. This includes separating out how to consider mechanical and chemical influences during manufacturing, the role of the chosen hardware and the challenges of aqueous formulation based on similar challenges being faced by the printing industry. Together, this provides a review of existing work and guidance for researchers and industry to help with the de-risking and rapid development of future biopharmaceutical products.
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Affiliation(s)
| | | | | | - Etienne Rognin
- Institute for Manufacturing, Department of Engineering, University of Cambridge (UK), UK
| | | | - Ronan Daly
- Institute for Manufacturing, Department of Engineering, University of Cambridge (UK), UK.
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12
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Schneider MF, Fallah MA, Mess C, Obser T, Schneppenheim R, Alexander-Katz A, Schneider SW, Huck V. Platelet adhesion and aggregate formation controlled by immobilised and soluble VWF. BMC Mol Cell Biol 2020; 21:64. [PMID: 32917131 PMCID: PMC7488753 DOI: 10.1186/s12860-020-00309-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 08/26/2020] [Indexed: 11/21/2022] Open
Abstract
Background It has been demonstrated that von Willebrand factor (VWF) mediated platelet-endothelium and platelet-platelet interactions are shear dependent. The VWF’s mobility under dynamic conditions (e.g. flow) is pivotal to platelet adhesion and VWF-mediated aggregate formation in the cascade of VWF-platelet interactions in haemostasis. Results Combining microfluidic tools with fluorescence and reflection interference contrast microscopy (RICM), here we show, that specific deletions in the A-domains of the biopolymer VWF affect both, adhesion and aggregation properties independently. Intuitively, the deletion of the A1-domain led to a significant decrease in both adhesion and aggregate formation of platelets. Nevertheless, the deletion of the A2-domain revealed a completely different picture, with a significant increase in formation of rolling aggregates (gain of function). We predict that the A2-domain effectively ‘masks’ the potential between the platelet glycoprotein (GP) Ib and the VWF A1-domain. Furthermore, the deletion of the A3-domain led to no significant variation in either of the two functional characteristics. Conclusions These data demonstrate that the macroscopic functional properties i.e. adhesion and aggregate formation cannot simply be assigned to the properties of one particular domain, but have to be explained by cooperative phenomena. The absence or presence of molecular entities likewise affects the properties (thermodynamic phenomenology) of its neighbours, therefore altering the macromolecular function.
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Affiliation(s)
- Matthias F Schneider
- Department of Physics, Medical and Biological Physics, Technical University Dortmund, Emil-Figge-Str. 50, 44227, Dortmund, Germany
| | - Mohammad A Fallah
- Department of Chemistry, University of Konstanz, Universitätsstr. 10, 78457, Constance, Germany
| | - Christian Mess
- University Medical Centre Hamburg-Eppendorf, Centre for Internal Medicine, Martinistr. 52, 20246, Hamburg, Germany
| | - Tobias Obser
- Department of Paediatric Haematology and Oncology, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Reinhard Schneppenheim
- Department of Paediatric Haematology and Oncology, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany
| | - Alfredo Alexander-Katz
- Department of Materials Science and Engineerin, Massachusetts Institute of Technology, 400 Technology Sq. (NE46-605), Cambridge, MA, 02139, USA
| | - Stefan W Schneider
- University Medical Centre Hamburg-Eppendorf, Centre for Internal Medicine, Martinistr. 52, 20246, Hamburg, Germany
| | - Volker Huck
- University Medical Centre Hamburg-Eppendorf, Centre for Internal Medicine, Martinistr. 52, 20246, Hamburg, Germany. .,Heidelberg University, Medical Faculty Mannheim, Experimental Dermatology, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
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13
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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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14
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Solomon-Degefa H, Gebauer JM, Jeffries CM, Freiburg CD, Meckelburg P, Bird LE, Baumann U, Svergun DI, Owens RJ, Werner JM, Behrmann E, Paulsson M, Wagener R. Structure of a collagen VI α3 chain VWA domain array: adaptability and functional implications of myopathy causing mutations. J Biol Chem 2020; 295:12755-12771. [PMID: 32719005 DOI: 10.1074/jbc.ra120.014865] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/16/2020] [Indexed: 12/23/2022] Open
Abstract
Collagen VI is a ubiquitous heterotrimeric protein of the extracellular matrix (ECM) that plays an essential role in the proper maintenance of skeletal muscle. Mutations in collagen VI lead to a spectrum of congenital myopathies, from the mild Bethlem myopathy to the severe Ullrich congenital muscular dystrophy. Collagen VI contains only a short triple helix and consists primarily of von Willebrand factor type A (VWA) domains, protein-protein interaction modules found in a range of ECM proteins. Disease-causing mutations occur commonly in the VWA domains, and the second VWA domain of the α3 chain, the N2 domain, harbors several such mutations. Here, we investigate structure-function relationships of the N2 mutations to shed light on their possible myopathy mechanisms. We determined the X-ray crystal structure of N2, combined with monitoring secretion efficiency in cell culture of selected N2 single-domain mutants, finding that mutations located within the central core of the domain severely affect secretion efficiency. In longer α3 chain constructs, spanning N6-N3, small-angle X-ray scattering demonstrates that the tandem VWA array has a modular architecture and samples multiple conformations in solution. Single-particle EM confirmed the presence of multiple conformations. Structural adaptability appears intrinsic to the VWA domain region of collagen VI α3 and has implications for binding interactions and modulating stiffness within the ECM.
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Affiliation(s)
| | - Jan M Gebauer
- Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Cy M Jeffries
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Carolin D Freiburg
- Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany
| | | | - Louise E Bird
- The Research Complex at Harwell, Rutherford Appleton Laboratory Harwell, Oxford, United Kingdom.,Structural Biology Division, Wellcome Human Genetics Centre, University of Oxford, Oxford, United Kingdom
| | - Ulrich Baumann
- Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Dmitri I Svergun
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
| | - Raymond J Owens
- The Research Complex at Harwell, Rutherford Appleton Laboratory Harwell, Oxford, United Kingdom.,Structural Biology Division, Wellcome Human Genetics Centre, University of Oxford, Oxford, United Kingdom
| | - Jörn M Werner
- School of Biological Sciences, University of Southampton, Southampton, United Kingdom
| | - Elmar Behrmann
- Institute of Biochemistry, University of Cologne, Cologne, Germany.,Max Planck Research Group Structural Dynamics of Proteins, Center of Advanced European Studies and Research (caesar), Bonn, Germany
| | - Mats Paulsson
- Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany.,Center for Molecular Medicine (CMMC), Cologne, Germany.,Cologne Center for Musculoskeletal Biomechanics (CCMB), Cologne, Germany
| | - Raimund Wagener
- Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany .,Center for Molecular Medicine (CMMC), Cologne, Germany.,Cologne Center for Musculoskeletal Biomechanics (CCMB), Cologne, Germany
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15
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Tiede A, Zieger B, Lisman T. Acquired bleeding disorders. Haemophilia 2020; 27 Suppl 3:5-13. [PMID: 32476241 DOI: 10.1111/hae.14033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/23/2020] [Indexed: 12/19/2022]
Abstract
Acquired bleeding disorders can accompany hematological, neoplastic, autoimmune, cardiovascular or liver diseases, but can sometimes also arise spontaneously. They can manifest as single factor deficiencies or as complex hemostatic abnormalities. This review addresses (a) acquired hemophilia A, an autoimmune disorder characterized by inhibitory autoantibodies against coagulation factor VIII; (b) acquired von Willebrand syndrome in patients with cardiovascular disorders, where shear stress abnormalities result in destruction of von Willebrand factor; and (c) liver function disorders that comprise complex changes in pro- and anti-hemostatic factors, whose clinical implications are often difficult to predict. The article provides an overview on the pathophysiology, diagnostic tests and state-of-the-art treatment strategies.
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Affiliation(s)
- Andreas Tiede
- Hematology, Hemostasis, Oncology and Stem Cell Transplantation, Hannover Medical School, Hannover, Germany
| | - Barbara Zieger
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ton Lisman
- Surgical Research Laboratory and Section of Hepatobiliary Surgery and Liver Transplantation, Department of Surgery, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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16
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Injury Characteristics and von Willebrand Factor for the Prediction of Acute Respiratory Distress Syndrome in Patients With Burn Injury: Development and Internal Validation. Ann Surg 2020; 270:1186-1193. [PMID: 29697443 DOI: 10.1097/sla.0000000000002795] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To derive and validate a prediction model for the development of ARDS in burn-injured patients. SUMMARY BACKGROUND DATA Burn injury carries the highest incidence of acute respiratory distress syndrome (ARDS) among all predisposing conditions, but few studies exist on risk factors in these patients. Studies employing biomarkers and clinical risk factors for predicting ARDS mortality have recently been examined but none exist for onset of ARDS nor in patients with burn injury. METHODS This was a prospective multicenter study of 113 patients with isolated burn injury or inhalation injury. Clinical variables and plasma biomarkers representative of endothelial injury, epithelial injury, or inflammation were collected within 24 hours of admission. The most parsimonious model was chosen by considering discrimination, calibration, and model fit. RESULTS Among the biomarkers measured in patients with burn injuries, a one-standard deviation increase in log-transformed levels of the A2 domain of von Willebrand factor in the first 24 hours was most strongly associated with the development of ARDS (OR 7.72; 95% CI: 1.64-36.28, P = 0.03). Of candidate models, a 3-variable model with %TBSA, inhalation injury, and von Willebrand factor-A2 had comparable discrimination to more complex models (area under the curve: 0.90; 95% CI 0.85-0.96). The 3-variable model had good model fit by Hosmer-Lemeshow test (P = 0.74) and maintained similar discrimination after accounting for performance optimism (Bootstrapped area under the curve: 0.90; 95% CI: 0.84-0.95). CONCLUSIONS The 3-variable model with %TBSA, inhalation injury, and von Willebrand factor could be used to better identify at-risk patients for both the study and prevention of ARDS in patients with burn injury.
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17
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Taylor C, Bittner K, Bartell N, Aranez J, Alexis JD, Carlson B, Chen L, McNitt S, Kothari T, Kaul V, Kothari S. Outcomes of gastrointestinal bleeding in patients with left ventricular assist devices: a tertiary care experience. Endosc Int Open 2020; 8:E301-E309. [PMID: 32140555 PMCID: PMC7055617 DOI: 10.1055/a-1090-7200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 10/28/2019] [Indexed: 02/06/2023] Open
Abstract
Background and study aims Left ventricular assist device (LVAD) placement is a therapeutic modality for patients with end-stage heart failure. Gastrointestinal bleeding is a common complication following LVAD implantation. The aim of this study was to report our experience in management and outcomes of gastrointestinal bleeding in a large cohort of patients with LVADs. Patients and methods We performed a retrospective review of all patients who underwent LVAD implantation at the University of Rochester Medical Center from January 2008 to June 2017. Data were collected on patient characteristics, clinical aspects of gastrointestinal bleeding events, and procedural interventions. A Cox proportional hazard model was utilized to identify potential risk factors for a gastrointestinal bleeding event. Results During the study period, 345 patients underwent LVAD implantation. Of these, 125 patients (36.2 %) experienced 297 gastrointestinal bleeding events resulting in 533 endoscopic procedures. The diagnostic yield of endoscopy in determining a bleeding source was 49.5 %. If required, therapeutic interventions were successful in achieving homeostasis in 96.2 % of procedures. Our 30-day overall post-procedure adverse event (AE) rate was 6.6 %. Procedure-related (bleeding, infection, and perforation) AEs were very minimal (2.8 %). A Cox proportional hazard model indicated that older age at implant, female sex, African-American race, diabetes mellitus, and pulmonary hypertension were statistically significant predictors of a gastrointestinal bleeding event following LVAD implantation. Conclusions LVAD patients have a high risk of gastrointestinal bleeding. Endoscopy was able to safely locate a bleeding lesion in approximately half of our patients and was successful in treating bleeding lesions in a majority of the cases.
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Affiliation(s)
- Caren Taylor
- Center for Advanced Therapeutic Endoscopy, Division of Gastroenterology & Hepatology, University of Rochester Medical Center, Rochester New York, United States
| | - Krystle Bittner
- Center for Advanced Therapeutic Endoscopy, Division of Gastroenterology & Hepatology, University of Rochester Medical Center, Rochester New York, United States
| | - Nicholas Bartell
- Center for Advanced Therapeutic Endoscopy, Division of Gastroenterology & Hepatology, University of Rochester Medical Center, Rochester New York, United States
| | - Jose Aranez
- Center for Advanced Therapeutic Endoscopy, Division of Gastroenterology & Hepatology, University of Rochester Medical Center, Rochester New York, United States
| | - Jeffrey D Alexis
- Division of Cardiology, University of Rochester Medical Center, Rochester New York, United States
| | - Beth Carlson
- Division of Cardiology, University of Rochester Medical Center, Rochester New York, United States
| | - Leway Chen
- Division of Cardiology, University of Rochester Medical Center, Rochester New York, United States
| | - Scott McNitt
- Division of Cardiology, University of Rochester Medical Center, Rochester New York, United States
| | - Truptesh Kothari
- Center for Advanced Therapeutic Endoscopy, Division of Gastroenterology & Hepatology, University of Rochester Medical Center, Rochester New York, United States
| | - Vivek Kaul
- Center for Advanced Therapeutic Endoscopy, Division of Gastroenterology & Hepatology, University of Rochester Medical Center, Rochester New York, United States
| | - Shivangi Kothari
- Center for Advanced Therapeutic Endoscopy, Division of Gastroenterology & Hepatology, University of Rochester Medical Center, Rochester New York, United States
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18
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Chowdhury SR, Jaiswal S, Lu HP. Compressive-force induced activation of apo-calmodulin in protein signalling. Phys Chem Chem Phys 2020; 22:1092-1096. [PMID: 31894209 DOI: 10.1039/c9cp05074d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mechanical force plays a critical role in the relationship between protein structure and function. Force manipulation by Atomic Force Microscope can be significant and trigger chemical and biological activities of proteins. Previously we have reported that Apo-CaM undergoes through a spontaneous tertiary structural rupture under a piconewton compressive force. Here we have observed that the ruptured Apo-CaM molecules can be available to bind with C28W peptide, a typical protein signalling activity that only a Ca2+-activated CaM has. This behaviour is both unexpected and profound, as CaM in its Ca2+-non-activated form has a closed structure which does not presumably allow the molecule to bind to target peptides. In this experiment, we demonstrate that both chemical activation and force activation can play a vital role in biology, such as the cell-signalling protein dynamics and function.
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Affiliation(s)
- Susovan Roy Chowdhury
- Department of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA.
| | - Sunidhi Jaiswal
- Department of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA.
| | - H Peter Lu
- Department of Chemistry, Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA.
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19
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Multiplexed protein force spectroscopy reveals equilibrium protein folding dynamics and the low-force response of von Willebrand factor. Proc Natl Acad Sci U S A 2019; 116:18798-18807. [PMID: 31462494 PMCID: PMC6754583 DOI: 10.1073/pnas.1901794116] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Single-molecule force spectroscopy has provided unprecedented insights into protein folding, force regulation, and function. So far, the field has relied primarily on atomic force microscope and optical tweezers assays that, while powerful, are limited in force resolution, throughput, and require feedback for constant force measurements. Here, we present a modular approach based on magnetic tweezers (MT) for highly multiplexed protein force spectroscopy. Our approach uses elastin-like polypeptide linkers for the specific attachment of proteins, requiring only short peptide tags on the protein of interest. The assay extends protein force spectroscopy into the low force (<1 pN) regime and enables parallel and ultra-stable measurements at constant forces. We present unfolding and refolding data for the small, single-domain protein ddFLN4, commonly used as a molecular fingerprint in force spectroscopy, and for the large, multidomain dimeric protein von Willebrand factor (VWF) that is critically involved in primary hemostasis. For both proteins, our measurements reveal exponential force dependencies of unfolding and refolding rates. We directly resolve the stabilization of the VWF A2 domain by Ca2+ and discover transitions in the VWF C domain stem at low forces that likely constitute the first steps of VWF's mechano-activation. Probing the force-dependent lifetime of biotin-streptavidin bonds, we find that monovalent streptavidin constructs with specific attachment geometry are significantly more force stable than commercial, multivalent streptavidin. We expect our modular approach to enable multiplexed force-spectroscopy measurements for a wide range of proteins, in particular in the physiologically relevant low-force regime.
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20
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Pill MF, East ALL, Marx D, Beyer MK, Clausen‐Schaumann H. Mechanical Activation Drastically Accelerates Amide Bond Hydrolysis, Matching Enzyme Activity. Angew Chem Int Ed Engl 2019; 58:9787-9790. [DOI: 10.1002/anie.201902752] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/10/2019] [Indexed: 01/21/2023]
Affiliation(s)
- Michael F. Pill
- Department of Applied Sciences and MechatronicsMunich University of Applied Sciences Lothstrasse 34 80334 Munich Germany
- Center for Nanoscience (CeNS) Schellingstrasse 4 80799 Munich Germany
| | - Allan L. L. East
- Department of Chemistry and BiochemistryUniversity of Regina Regina SK S4S0A2 Canada
| | - Dominik Marx
- Lehrstuhl für Theoretische ChemieRuhr-Universität Bochum 44780 Bochum Germany
| | - Martin K. Beyer
- Institut für Ionenphysik und Angewandte PhysikUniversität Innsbruck Technikerstrasse 25 6020 Innsbruck Austria
| | - Hauke Clausen‐Schaumann
- Department of Applied Sciences and MechatronicsMunich University of Applied Sciences Lothstrasse 34 80334 Munich Germany
- Center for Nanoscience (CeNS) Schellingstrasse 4 80799 Munich Germany
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21
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Pill MF, East ALL, Marx D, Beyer MK, Clausen‐Schaumann H. Mechanische Aktivierung beschleunigt die Hydrolyse der Amidbindung drastisch, vergleichbar der Aktivität von Enzymen. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902752] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Michael F. Pill
- Fakultät für angewandte Naturwissenschaften und MechatronikHochschule für angewandte Wissenschaften München Lothstraße 34 80334 München Deutschland
- Center for Nanoscience (CeNS) Schellingstraße 4 80799 München Deutschland
| | - Allan L. L. East
- Department of Chemistry and BiochemistryUniversity of Regina Regina SK S4S0A2 Kanada
| | - Dominik Marx
- Lehrstuhl für Theoretische ChemieRuhr-Universität Bochum 44780 Bochum Deutschland
| | - Martin K. Beyer
- Institut für Ionenphysik und Angewandte PhysikUniversität Innsbruck Technikerstraße 25 6020 Innsbruck Österreich
| | - Hauke Clausen‐Schaumann
- Fakultät für angewandte Naturwissenschaften und MechatronikHochschule für angewandte Wissenschaften München Lothstraße 34 80334 München Deutschland
- Center for Nanoscience (CeNS) Schellingstraße 4 80799 München Deutschland
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22
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Newnham M, South K, Bleda M, Auger WR, Barberà JA, Bogaard H, Bunclark K, Cannon JE, Delcroix M, Hadinnapola C, Howard LS, Jenkins D, Mayer E, Ng C, Rhodes CJ, Screaton N, Sheares K, Simpson MA, Southwood M, Su L, Taboada D, Traylor M, Trembath RC, Villar SS, Wilkins MR, Wharton J, Gräf S, Pepke-Zaba J, Laffan M, Lane DA, Morrell NW, Toshner M. The ADAMTS13-VWF axis is dysregulated in chronic thromboembolic pulmonary hypertension. Eur Respir J 2019; 53:13993003.01805-2018. [PMID: 30655285 PMCID: PMC6437602 DOI: 10.1183/13993003.01805-2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 12/19/2018] [Indexed: 01/08/2023]
Abstract
Chronic thromboembolic pulmonary hypertension (CTEPH) is an important consequence of pulmonary embolism that is associated with abnormalities in haemostasis. We investigated the ADAMTS13–von Willebrand factor (VWF) axis in CTEPH, including its relationship with disease severity, inflammation, ABO groups and ADAMTS13 genetic variants. ADAMTS13 and VWF plasma antigen levels were measured in patients with CTEPH (n=208), chronic thromboembolic disease without pulmonary hypertension (CTED) (n=35), resolved pulmonary embolism (n=28), idiopathic pulmonary arterial hypertension (n=30) and healthy controls (n=68). CTEPH genetic ABO associations and protein quantitative trait loci were investigated. ADAMTS13–VWF axis abnormalities were assessed in CTEPH and healthy control subsets by measuring ADAMTS13 activity, D-dimers and VWF multimeric size. Patients with CTEPH had decreased ADAMTS13 (adjusted β −23.4%, 95% CI −30.9– −15.1%, p<0.001) and increased VWF levels (β +75.5%, 95% CI 44.8–113%, p<0.001) compared to healthy controls. ADAMTS13 levels remained low after reversal of pulmonary hypertension by pulmonary endarterectomy surgery and were equally reduced in CTED. We identified a genetic variant near the ADAMTS13 gene associated with ADAMTS13 protein that accounted for ∼8% of the variation in levels. The ADAMTS13–VWF axis is dysregulated in CTEPH. This is unrelated to pulmonary hypertension, disease severity or markers of systemic inflammation and implicates the ADAMTS13–VWF axis in CTEPH pathobiology. The ADAMTS-13–VWF axis is dysregulated in chronic thromboembolism with and without pulmonary hypertension and is implicated in the pathogenesishttp://ow.ly/J9SC30nh5T0
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Affiliation(s)
- Michael Newnham
- Dept of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,Royal Papworth Hospital, Cambridge, UK
| | - Kieron South
- Centre for Haematology, Imperial College London, London, UK
| | - Marta Bleda
- Dept of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | | | - Joan A Barberà
- Hospital Clínic - IDIBAPS-CIBER Enfermedades Respiratorias, University of Barcelona, Barcelona, Spain
| | - Harm Bogaard
- VU University Medical Centre, Amsterdam, The Netherlands
| | | | | | | | - Charaka Hadinnapola
- Dept of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Luke S Howard
- Hammersmith Hospital, Imperial College Healthcare NHS Trust, London, UK
| | | | - Eckhard Mayer
- Kerckhoff Heart and Lung Centre, Bad Nauheim, Germany
| | - Choo Ng
- Royal Papworth Hospital, Cambridge, UK
| | - Christopher J Rhodes
- Centre for Pharmacology and Therapeutics, Dept of Medicine, Hammersmith Campus, Imperial College London, London, UK
| | | | | | - Michael A Simpson
- Dept of Medical and Molecular Genetics, King's College London School of Basic and Medical Biosciences, London, UK
| | | | - Li Su
- MRC Biostatistics Unit, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | | | - Matthew Traylor
- Dept of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Richard C Trembath
- Dept of Medical and Molecular Genetics, King's College London School of Basic and Medical Biosciences, London, UK
| | - Sofia S Villar
- MRC Biostatistics Unit, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Martin R Wilkins
- Centre for Pharmacology and Therapeutics, Dept of Medicine, Hammersmith Campus, Imperial College London, London, UK
| | - John Wharton
- Centre for Pharmacology and Therapeutics, Dept of Medicine, Hammersmith Campus, Imperial College London, London, UK
| | - Stefan Gräf
- Dept of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,Dept of Haematology, National Health Service Blood and Transplant Centre, University of Cambridge, Cambridge, UK.,National Institute of Health Research BioResource for Translational Research, Cambridge Biomedical Campus, Cambridge, UK
| | | | - Michael Laffan
- Centre for Haematology, Imperial College London, London, UK
| | - David A Lane
- Centre for Haematology, Imperial College London, London, UK
| | - Nicholas W Morrell
- Dept of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Mark Toshner
- Dept of Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.,Royal Papworth Hospital, Cambridge, UK
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23
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Association of Oxidative Stress and Platelet Receptor Glycoprotein GPIbα and GPVI Shedding During Nonsurgical Bleeding in Heart Failure Patients With Continuous-Flow Left Ventricular Assist Device Support. ASAIO J 2019; 64:462-471. [PMID: 28953486 DOI: 10.1097/mat.0000000000000680] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Nonsurgical bleeding (NSB) in heart failure (HF) patients with continuous-flow left ventricular assist device (CF-LVAD) support is the most common clinical complication. The aim of this study was to investigate the association between oxidative stress and platelet glycoproteins GPIbα and GPVI shedding on the incidence of NSB in CF-LVAD patients. Fifty-one HF patients undergoing CF-LVAD implantation and 11 healthy volunteers were recruited. Fourteen patients developed NSB (bleeder group) during 1 month follow-up duration, while others were considered nonbleeder group (n = 37). Several biomarkers of oxidative stress were quantified at baseline and weekly intervals in all patients. Surface expression and plasma elements of platelet receptor glycoproteins GPIbα and GPVI were measured. Oxidative stress biomarkers and platelet GPIbα and GPVI receptor-shedding (decreased surface expression and higher plasma levels) were found to be preexisting conditions in baseline samples of both groups of HF patients when compared with healthy volunteers. Significantly elevated oxidative stress biomarkers and platelet glycoprotein receptor shedding were observed in postimplant bleeder group temporarily when compared with nonbleeder group. Strong significant associations between biomarkers of oxidative stress and platelet glycoprotein receptor shedding were observed, suggesting a possible role of oxidative stress in platelet integrin shedding leading to NSB in CF-LVAD patients. Receiver operating characteristic analyses of GPIbα and GPVI indicated that the likelihood of NSB had a predictive power of bleeding complication in CF-LVAD patients. In conclusion, elevated oxidative stress may play a role in GPIbα and GPVI shedding in the event of NSB. Thus, oxidative stress and GPIbα and GPVI shedding may be used as potential biomarkers for bleeding risk stratification in those patients.
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24
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Klaeske K, Dieterlen MT, Scholz U, Lehmann S, Garbade J, Fischer J, Jawad K, Borger MA, Meyer A. Acquired von Willebrand factor deficiency is reduced in HeartMate 3 patients†. Eur J Cardiothorac Surg 2019; 56:444-450. [DOI: 10.1093/ejcts/ezz045] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 01/08/2019] [Accepted: 01/30/2019] [Indexed: 12/15/2022] Open
Abstract
Abstract
OBJECTIVES
The acquired von Willebrand syndrome (AvWS), which is associated with left ventricular assist device support, is caused by the loss of the von Willebrand factor (vWF) high molecular weight multimers (HMWMs). We investigated whether the implantation of the left ventricular assist device HeartMate 3 (HM 3) is superior to the HeartWare ventricular assist device (HVAD) in preserving the multimeric structure of vWF.
METHODS
In total, 70 patients with implanted HM 3 (n = 35) or HVAD (n = 35) were retrospectively investigated. HMWMs, intermediate molecular weight multimers and low molecular weight multimers were quantified by using a densitometric methodology. vWF antigen, vWF activity and vWF collagen-binding activity, as well as demographic and clinical data, were analysed.
RESULTS
AvWS, which is characterized by a decrease in vWF HMWMs, was found in 97.1% of patients in the HM 3 group and 100% of patients in the HVAD group. Compared to normal pooled plasma, HM 3 induced a reduction in HMWMs (40.7 ± 8.2% vs 26.7 ± 7.5%, P < 0.01) and an increase in low molecular weight multimers (31.3 ± 11.8% vs 42.7 ± 9.8%, P < 0.01), whereas HVAD patients exhibited an increase in the percentage of intermediate molecular weight multimers (28.0 ± 5.0% vs 38.4 ± 7.7%, P < 0.01) in addition to a decrease in the percentage of HMWM (23.0 ± 11.0%, P < 0.01). A comparison of both left ventricular assist device types showed a difference in vWF multimeric structure (HMWMs: P < 0.01, intermediate molecular weight multimer: P = 0.05, low molecular weight multimer: P = 0.03). Furthermore, vWF activity was elevated in patients with an implanted HM 3 device (153.7 ± 54.4%) compared to those with an HVAD device (126.3 ± 39.7%, P = 0.02).
CONCLUSIONS
Patients with an implanted HM 3 had more intact HMWMs and a higher vWF activity during device support. This may reduce the manifestation of AvWS in HM 3 patients and could thus lead to a lower bleeding complication rate.
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Affiliation(s)
- Kristin Klaeske
- Department of Cardiac Surgery, University of Leipzig, Heart Center Leipzig, Helios Clinic, Leipzig, Germany
| | - Maja-Theresa Dieterlen
- Department of Cardiac Surgery, University of Leipzig, Heart Center Leipzig, Helios Clinic, Leipzig, Germany
| | - Ute Scholz
- Zentrum für Blutgerinnungsstörungen, MVZ Labor Dr. Reising-Ackermann und Kollegen, Leipzig, Germany
| | - Sven Lehmann
- Department of Cardiac Surgery, University of Leipzig, Heart Center Leipzig, Helios Clinic, Leipzig, Germany
| | - Jens Garbade
- Department of Cardiac Surgery, University of Leipzig, Heart Center Leipzig, Helios Clinic, Leipzig, Germany
| | - Julia Fischer
- Department of Cardiac Surgery, University of Leipzig, Heart Center Leipzig, Helios Clinic, Leipzig, Germany
| | - Khalil Jawad
- Department of Cardiac Surgery, University of Leipzig, Heart Center Leipzig, Helios Clinic, Leipzig, Germany
| | - Michael A Borger
- Department of Cardiac Surgery, University of Leipzig, Heart Center Leipzig, Helios Clinic, Leipzig, Germany
| | - Anna Meyer
- Department of Cardiac Surgery, University of Leipzig, Heart Center Leipzig, Helios Clinic, Leipzig, Germany
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25
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Herrera-Rodríguez AM, Miletić V, Aponte-Santamaría C, Gräter F. Molecular Dynamics Simulations of Molecules in Uniform Flow. Biophys J 2019; 116:1579-1585. [PMID: 30975453 DOI: 10.1016/j.bpj.2018.12.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/09/2018] [Accepted: 12/11/2018] [Indexed: 01/13/2023] Open
Abstract
Flow at the molecular level induces shear-induced unfolding of single proteins and can drive their assembly, the mechanisms of which are not completely understood. To be able to analyze the role of flow on molecules, we present uniform-flow molecular dynamics simulations at atomic level. The pull module of the GRoningen MAchine for Chemical Simulations package was extended to be able to force-group atoms within a defined layer of the simulation box. Application of this external enforcement to explicit water molecules, together with the coupling to a thermostat, led to a uniform terminal velocity of the solvent water molecules. We monitored the density of the whole system to establish the conditions under which the simulated flow is well-behaved. A maximal velocity of 1.3 m/s can be generated if a pull slice of 8 nm is used, and high velocities would require larger pull slices to still maintain a stable density. As expected, the target velocity increases linearly with the total external force applied. Finally, we suggest an appropriate setup to stretch a protein by uniform flow, in which protein extensions depend on the flow conditions. Our implementation provides an efficient computational tool to investigate the effect of the flow at the molecular level.
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Affiliation(s)
| | - Vedran Miletić
- Heidelberg Institute for Theoretical Studies, Heidelberg, Germany; Biomolecular Structure and Function Laboratory, Department of Informatics, University of Rijeka, Rijeka, Croatia
| | - Camilo Aponte-Santamaría
- Max Planck Tandem Group in Computational Biophysics, Universidad of los Andes, Bogotá, Colombia; Interdisciplinary Center for Scientific Computing, Heidelberg University, Mathematikon, Heidelberg, Germany
| | - Frauke Gräter
- Heidelberg Institute for Theoretical Studies, Heidelberg, Germany; Interdisciplinary Center for Scientific Computing, Heidelberg University, Mathematikon, Heidelberg, Germany.
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Eickmeyer SM, Barker KD, Sayyad A, Rydberg L. The Rehabilitation of Patients With Advanced Heart Failure After Left Ventricular Assist Device Placement: A Narrative Review. PM R 2019; 11:64-75. [PMID: 29929019 DOI: 10.1016/j.pmrj.2018.05.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/17/2018] [Indexed: 01/18/2023]
Abstract
Because more patients with advanced heart failure are receiving a left ventricular assist device (LVAD) as destination therapy or a bridge to transplantation, there is increasing attention on functional outcomes and quality of life after LVAD implantation. Rehabilitation providers in the acute inpatient rehabilitation setting increasingly will treat patients with an LVAD and should understand the exercise physiology, medical management, rehabilitation considerations, and outcomes after rehabilitation for patients with an LVAD. The purpose of this article is to provide the physiatrist with a comprehensive understanding of the rehabilitation of patients with advanced heart failure and LVAD implantation. Changes in relevant organ system physiology and exercise physiology after LVAD are summarized. Safety of rehabilitation and program considerations for acute inpatient rehabilitation are reviewed. Recommendations for medical management and prevention of secondary complications seen in patients with an LVAD are outlined. A discussion of outcomes after acute inpatient rehabilitation, the dual diagnosis of stroke and LVAD placement, and long-term cognitive, functional, and quality-of-life outcomes after LVAD placement is presented.
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Affiliation(s)
- Sarah M Eickmeyer
- Department of Rehabilitation Medicine, University of Kansase-Kansas City, 3901 Rainbow Blvd, Kansas City, KS 66160
| | - Kim D Barker
- Department of Physical Medicine and Rehabilitation, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Anjum Sayyad
- Department of Physical Medicine and Rehabilitation, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois; Marianjoy Rehabilitation Hospital, Wheaton, Illinois
| | - Leslie Rydberg
- Department of Physical Medicine and Rehabilitation, Northwestern University Feinberg School of Medicine, Chicago, Illinois; Shirley Ryan AbilityLab, Chicago, Illinois
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Wijeratne SS, Nolasco L, Li J, Jiang K, Moake JL, Kiang CH. Correlating Conformational Dynamics with the Von Willebrand Factor Reductase Activity of Factor H Using Single Molecule Force Measurements. J Phys Chem B 2018; 122:10653-10658. [PMID: 30351116 DOI: 10.1021/acs.jpcb.8b06153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Activation of proteins often involves conformational transitions, and these switches are often difficult to characterize in multidomain proteins. Full-length factor H (FH), consisting of 20 small consensus repeat domains (150 kD), is a complement control protein that regulates the activity of the alternative complement pathway. Different preparations of FH can also reduce the disulfide bonds linking large Von Willebrand factor (VWF) multimers into smaller, less adhesive forms. In contrast, commercially available purified FH (pFH) has little or no VWF reductase activity unless the pFH is chemically modified by either ethylenediaminetetraacetic acid (EDTA) or urea. We used atomic force microscopy single molecule force measurements to investigate different forms of FH, including recombinant FH and pFH, in the presence or absence of EDTA and urea, and to correlate the conformational changes to its activities. We found that the FH conformation depends on the method used for sample preparation, which affects the VWF reductase activity of FH.
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Jhun CS, Siedlecki C, Xu L, Lukic B, Newswanger R, Yeager E, Reibson J, Cysyk J, Weiss W, Rosenberg G. Stress and Exposure Time on von Willebrand Factor Degradation. Artif Organs 2018; 43:199-206. [PMID: 30374981 DOI: 10.1111/aor.13323] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/14/2018] [Accepted: 06/22/2018] [Indexed: 12/13/2022]
Abstract
Despite the prevailing use of the continuous flow left ventricular assist devices (cf-LVAD), acquired von Willebrand syndrome (AvWS) associated with cf-LVAD still remains a major complication. As AvWS is known to be dependent on shear stress (τ) and exposure time (texp ), this study examined the degradation of high molecular weight multimers (HMWM) of von Willebrand factor (vWF) in terms of τ and texp . Two custom apparatus, i.e., capillary-tubing-type degrader (CTD) and Taylor-Couette-type degrader (TCD) were developed for short-term (0.033 sec ≤ texp ≤ 1.05 s) and long-term (10 s ≤ texp ≤ 10 min) shear exposures of vWF, respectively. Flow conditions indexed by Reynolds number (Re) for CTD were 14 ≤ Re ≤ 288 with corresponding laminar stress level of 52 ≤ τ CTD ≤ 1042 dyne/cm2 . Flow conditions for TCD were 100 ≤ Re ≤ 2500 with corresponding rotor speed of 180 ≤ o ≤ 4000 RPM and laminar stress level of 50 ≤ τ TCD ≤ 1114 dyne/cm2 . Due to transitional and turbulent flows in TCD at Re > 1117, total stress (i.e., τ total = laminar + turbulent) was also calculated using a computational fluid dynamics (CFD) solver, Converge CFD (Converge Science Inc., Madison, WI, USA). Inhibition of ADAMTS13 with different concentration of EDTA (5 mM and 10 mM) was also performed to investigate the mechanism of cleavage in terms of mechanical and enzymatic aspects. Degradation of HMWM with CTD was negligible at all given testing conditions. Although no degradation of HMWM was observed with TCD at Re < 1117 ( τ total = 1012 dyne/cm2 ), increase in degradation of HMWM was observed beyond Re of 1117 for all given exposure times. At Re ~ 2500 ( τ total = 3070 dyne/cm2 ) with texp = 60 s, a severe degradation of HMWM (90.7 ± 3.8%, abnormal) was observed, and almost complete degradation of HMWM (96.1 ± 1.9%, abnormal) was observed with texp = 600 s. The inhibition studies with 5 mM EDTA at Re ~ 2500 showed that loss of HMWM was negligible (<10%, normal) for all given exposure times except for texp = 10 min (39.5 ± 22.3%, borderline-abnormal). With 10 mM EDTA, no degradation of HMWM was observed (11.1 ± 4.4%, normal) even for texp = 10 min. This study investigated the effect of shear stress and exposure time on the HMWM of vWF in laminar and turbulent flows. The inhibition study by EDTA confirms that degradation of HMWM is initiated by shear-induced unfolding followed by enzymatic cleavage at given conditions. Determination of magnitude of each mechanism needs further investigation. It is also important to note that the degradation of vWF is highly dependent on turbulence regardless of the time exposed within our testing conditions.
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Affiliation(s)
- Choon-Sik Jhun
- Division of Applied Biomedical Engineering, Department of Surgery, Penn State College of Medicine, Hershey PA, USA
| | - Christopher Siedlecki
- Division of Applied Biomedical Engineering, Department of Surgery, Penn State College of Medicine, Hershey PA, USA.,Department of Biomedical Engineering, Penn State University, University Park, PA, USA
| | - Lichong Xu
- Division of Applied Biomedical Engineering, Department of Surgery, Penn State College of Medicine, Hershey PA, USA
| | - Branka Lukic
- Division of Applied Biomedical Engineering, Department of Surgery, Penn State College of Medicine, Hershey PA, USA
| | - Raymond Newswanger
- Division of Applied Biomedical Engineering, Department of Surgery, Penn State College of Medicine, Hershey PA, USA
| | - Eric Yeager
- Division of Applied Biomedical Engineering, Department of Surgery, Penn State College of Medicine, Hershey PA, USA
| | - John Reibson
- Division of Applied Biomedical Engineering, Department of Surgery, Penn State College of Medicine, Hershey PA, USA
| | - Joshua Cysyk
- Division of Applied Biomedical Engineering, Department of Surgery, Penn State College of Medicine, Hershey PA, USA
| | - William Weiss
- Division of Applied Biomedical Engineering, Department of Surgery, Penn State College of Medicine, Hershey PA, USA.,Department of Biomedical Engineering, Penn State University, University Park, PA, USA
| | - Gerson Rosenberg
- Division of Applied Biomedical Engineering, Department of Surgery, Penn State College of Medicine, Hershey PA, USA.,Department of Biomedical Engineering, Penn State University, University Park, PA, USA
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Kalbhenn J, Schlagenhauf A, Rosenfelder S, Schmutz A, Zieger B. Acquired von Willebrand syndrome and impaired platelet function during venovenous extracorporeal membrane oxygenation: Rapid onset and fast recovery. J Heart Lung Transplant 2018; 37:985-991. [PMID: 29650295 DOI: 10.1016/j.healun.2018.03.013] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Revised: 02/18/2018] [Accepted: 03/14/2018] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Bleeding contributes to the high mortality of venovenous extracorporeal membrane oxygenation (vvECMO). The development of acquired von Willebrand syndrome (AVWS) has been identified as relevant pathology during ECMO. This study was performed to determine the onset of AVWS after implantation and the recovery of von Willebrand factor (VWF) parameters after explantation of ECMO in a large cohort of patients. METHODS VWF parameters of 59 patients treated with vvECMO at a university ECMO center were obtained before ECMO implantation, during therapy, and after explantation. In a subgroup of patients, light transmission aggregometry of platelets and flow-cytometric quantification of platelet granule secretion were performed. RESULTS All patients developed severe AVWS hours after implantation of vvECMO. After explantation, AVWS recovered within 3 hours in 60%, within 6 hours in 86%, and in all patients within 1 day. Aggregometry showed hypoaggregability of platelets after stimulation with ADP, ristocetin, collagen, and epinephrine. Flow-cytometric platelet analyses revealed severely reduced expression of CD62 and CD63. CONCLUSIONS All patients during vvECMO support rapidly develop AVWS and platelet dysfunction, resulting in severe impairment of coagulation. After explantation, AVWS overwhelmingly recovers within hours, resulting in a hypercoagulative state. These findings augment the need for novel extracorporeal technologies with reduced shear stress, and shift the emphasis for intense anti-coagulation during ECMO instead to a time-point after explantation.
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Affiliation(s)
- Johannes Kalbhenn
- Department of Anesthesiology and Critical Care, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
| | - Axel Schlagenhauf
- Department of Pediatrics and Adolescent Medicine, Medical University of Graz, Graz, Austria
| | - Simone Rosenfelder
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Axel Schmutz
- Department of Anesthesiology and Critical Care, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Barbara Zieger
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Hematology and Oncology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Chetcuti Zammit S, Koulaouzidis A, Sanders DS, McAlindon ME, Rondonotti E, Yung DE, Sidhu R. Overview of small bowel angioectasias: clinical presentation and treatment options. Expert Rev Gastroenterol Hepatol 2018; 12:125-139. [PMID: 28994309 DOI: 10.1080/17474124.2018.1390429] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Elderly patients with multiple co-morbidities are at an increased risk of developing small bowel angioectasias. Treating these lesions can be both challenging and costly with patients requiring extensive investigations and recurrent admissions for iron infusions and blood transfusions as well as invasive procedures. This review presents treatment options and describes in detail drugs that should be considered whilst taking into account their effectiveness and their safety profile. Areas covered: A PubMed search was carried out using the following keywords: small bowel angiodysplasias, small bowel angioectasias, small bowel bleeding and obscure gastrointestinal bleeding to assess existing evidence. The pathophysiology and risk factors are covered in this review together with appropriate methods of investigation and management. Treatment options discussed are endoscopic measures, surgical options and pharmacotherapy. The role of serum biomarkers is also discussed. Expert commentary: Future work should be directed at alternative drugs with a good safety profile that target biomarkers. Novel pharmacotherapy directed at biomarkers could potentially provide a non-invasive treatment option for angioectasias particularly in the elderly where management can be challenging.
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Affiliation(s)
| | | | - David S Sanders
- a Gastroenterology Department , Royal Hallamshire Hospital , Sheffield , UK
| | - Mark E McAlindon
- a Gastroenterology Department , Royal Hallamshire Hospital , Sheffield , UK
| | | | - Diana E Yung
- b Endoscopy Unit , the Royal Infirmary of Edinburgh , Edinburgh , UK
| | - Reena Sidhu
- a Gastroenterology Department , Royal Hallamshire Hospital , Sheffield , UK
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31
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Budde U, Schneppenheim R. Regulation der primären Hämostase durch von-Willebrand-Faktor und ADAMTS13. Hamostaseologie 2017; 31:275-80. [DOI: 10.5482/ha-1167] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 07/01/2011] [Indexed: 11/05/2022] Open
Abstract
SummaryVon Willebrand factor (VWF) is an adhesive, multi-functional huge multimerized protein with multiple domains harboring binding sites for collagen, platelet glycoprotein receptors and coagulation factor VIII (FVIII). The functional domains enable VWF to bind to the injured vessel wall, to recruit platelets to the site of injury by adhesion and aggregation and to bind and protect FVIII, an important cofactor of the coagulation cascade. VWF function in primary haemostasis is located in particular in the arterial and micro-circulation. This environment is exposed to high shear forces with hydrodynamic shear rates ranging over several orders of magnitude from 10–1 to 105 s-1 and requires particular mechanisms to enable platelet adhesion and aggregation under these variable conditions. The respective VWF function is strictly correlating with its multimer size. Lack or reduction of large VWF multimers is seen in patients with von Willebrand disease (VWD) type 2A which correlates with reduction of both VWF:platelet GPIb-binding and VWF:collagen binding and a bleeding phenotype. To prevent unlimited platelet adhesion and aggregation which is the cause of the microangiopathic disorder thrombotic thrombocytopenic purpura (TTP), VWF function is regulated by its specific protease ADAMTS13. Whereas a particular susceptibility of VWF to ADAMTS13 proteolysis is the cause of a frequent VWD type 2A phenotype, lack or dysfunction of ADAMTS13, either acquired by ADAMTS13 antibodies or by inherited ADAMTS13 deficiency (Upshaw-Schulman Syndrome), causes TTP. Therefore VWD and TTP represent the opposite manifestations of VWF related disorders, tightly linked to each other.
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32
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Zayat R, Khattab MA, Grottke O, Honickel M, Goetzenich A, Moza A, Stoppe C, Autschbach R, Tewarie L. Survival of HeartMate II Patients Despite Cessation of Anticoagulation - Outcomes and Hemostatic Analysis. Circ J 2017; 82:1309-1318. [PMID: 29237991 DOI: 10.1253/circj.cj-17-0897] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND In long-term left ventricular assist device (LVAD) therapy, recurrent bleeding events may justify cessation of anticoagulation therapy (AT). However, data about THE safety and risks of AT cessation in LVAD patients are scarce.Methods and Results:Between 2010 and 2015, 128 patients received a HeartMate II (HMII). Following recurrent bleeding events, we ceased vitamin K antagonist (VKA) therapy in 13 patients (10%) (no-VKA group). To characterize the hemostatic profile, we performed von Willebrand factor (vWF), platelet function (PF), and other hemostatic tests in all HMII patients. The incidence of pump thrombosis (PT), ischemic stroke (IS) and bleeding events in this HMII population was 4.7 %, 6.2% and 36.7%, respectively. Median survival without VKA was 435 days. No cases of PT and only 1 of IS occurred after AT discontinuation. All patients had impaired PF and acquired von Willebrand syndrome (AvWS). However, the vWF collagen-binding activity to antigen ratio before and after VKA cessation was significantly lower in the no-VKA group compared with the HMII population (0.60±0.12 vs. 0.73±0.14, P=0.006). The thrombin-antithrombin III complex (TAT) value was significantly higher in the no-VKA group (P=0.0005). CONCLUSIONS We experienced good results with AT cessation in specific HMII patients. The simultaneous onset of AvWS and high TAT values could explain at least in part the low thromboembolic rate in HMII patients without VKA.
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Affiliation(s)
- Rashad Zayat
- Department of Thoracic and Cardiovascular Surgery, RWTH University Hospital
| | | | | | | | - Andreas Goetzenich
- Department of Thoracic and Cardiovascular Surgery, RWTH University Hospital
| | - Ajay Moza
- Department of Thoracic and Cardiovascular Surgery, RWTH University Hospital
| | | | - Rüdiger Autschbach
- Department of Thoracic and Cardiovascular Surgery, RWTH University Hospital
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Lynch CJ, Cawte AD, Millar CM, Rueda D, Lane DA. A common mechanism by which type 2A von Willebrand disease mutations enhance ADAMTS13 proteolysis revealed with a von Willebrand factor A2 domain FRET construct. PLoS One 2017; 12:e0188405. [PMID: 29186156 PMCID: PMC5706690 DOI: 10.1371/journal.pone.0188405] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/06/2017] [Indexed: 12/15/2022] Open
Abstract
Rheological forces in the blood trigger the unfolding of von Willebrand factor (VWF) and its A2 domain, exposing the scissile bond for proteolysis by ADAMTS13. Under quiescent conditions, the scissile bond is hidden by the folded structure due to the stabilisation provided by the structural specialisations of the VWF A2 domain, a vicinal disulphide bond, a calcium binding site and a N1574-glycan.The reduced circulating high MW multimers of VWF in patients with type 2A von Willebrand disease (VWD) may be associated with mutations within the VWF A2 domain and this is attributed to enhanced ADAMTS13 proteolysis. We investigated 11 VWF A2 domain variants identified in patients with type 2A VWD. In recombinant full-length VWF, enhanced ADAMTS13 proteolysis was detected for all of the expressed variants in the presence of urea-induced denaturation. A subset of the FLVWF variants displayed enhanced proteolysis in the absence of urea. The mechanism of enhancement was investigated using a novel VWF A2 domain FRET construct. In the absence of induced unfolding, 7/8 of the expressed mutants exhibited a disrupted domain fold, causing spatial separation of the N- and C- termini. Three of the type 2A mutants were not secreted when studied within the VWF A2 domain FRET construct. Urea denaturation revealed for all 8 secreted mutants reduced unfolding cooperativity and stability of the VWF A2 domain. As folding stability was progressively disrupted, proteolysis by ADAMTS13 increased. Due to the range of folding stabilities and wide distribution of VWF A2 domain mutations studied, we conclude that these mutations disrupt regulated folding of the VWF A2 domain. They enhance unfolding by inducing separation of N- and C-termini, thereby promoting a more open conformation that reveals its binding sites for ADAMTS13 and the scissile bond.
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Affiliation(s)
- Christopher J. Lynch
- Department of Medicine, Centre for Haematology, Imperial College London, United Kingdom
| | - Adam D. Cawte
- Department of Medicine, Molecular Virology, Imperial College, London, United Kingdom
- MRC London Institute of Medical Science, Single-Molecule Imaging Group, Imperial College, London, United Kingdom
| | - Carolyn M. Millar
- Department of Medicine, Centre for Haematology, Imperial College London, United Kingdom
- Imperial College Healthcare NHS Trust, Du Cane Road, London, United Kingdom
| | - David Rueda
- Department of Medicine, Molecular Virology, Imperial College, London, United Kingdom
- MRC London Institute of Medical Science, Single-Molecule Imaging Group, Imperial College, London, United Kingdom
| | - David A. Lane
- Department of Medicine, Centre for Haematology, Imperial College London, United Kingdom
- * E-mail:
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Becq A, Rahmi G, Perrod G, Cellier C. Hemorrhagic angiodysplasia of the digestive tract: pathogenesis, diagnosis, and management. Gastrointest Endosc 2017; 86:792-806. [PMID: 28554655 DOI: 10.1016/j.gie.2017.05.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 05/18/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Aymeric Becq
- Gastroenterology and Endoscopy division, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, University Paris-Descartes Sorbonne-Paris Cité, Paris, France
| | - Gabriel Rahmi
- Gastroenterology and Endoscopy division, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, University Paris-Descartes Sorbonne-Paris Cité, Paris, France
| | - Guillaume Perrod
- Gastroenterology and Endoscopy division, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, University Paris-Descartes Sorbonne-Paris Cité, Paris, France
| | - Christophe Cellier
- Gastroenterology and Endoscopy division, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, University Paris-Descartes Sorbonne-Paris Cité, Paris, France
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35
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Alsmadi NZ, Shapiro SJ, Lewis CS, Sheth VM, Snyder TA, Schmidtke DW. Constricted microfluidic devices to study the effects of transient high shear exposure on platelets. BIOMICROFLUIDICS 2017; 11:064105. [PMID: 29204246 PMCID: PMC5705242 DOI: 10.1063/1.4989386] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 11/02/2017] [Indexed: 06/07/2023]
Abstract
Due to the critical roles that platelets play in thrombosis during many biological and pathological events, altered platelet function may be a key contributor to altered hemostasis, leading to both thrombotic and hemorrhagic complications. Platelet adhesion at arterial shear rates occurs through binding to von Willebrand Factor via the glycoprotein (GP) GPIb receptor. GPIb binding can induce platelet activation distinguishable by P-selectin (CD62P) surface expression and αIIbβ3 activation, resulting in platelet aggregation and formation of the primary hemostatic plug to stop bleeding. Previous studies have used cone and plate viscometers to examine pathologic blood flow conditions, applied shear rates that are relatively low, and examined exposure times that are orders of magnitude longer compared to conditions present in ventricular assist devices, mechanical heart valves, or pathologic states such as stenotic arteries. Here, we evaluate the effect of short exposure to high shear on granule release and receptor shedding utilizing a constricted microfluidic device in conjunction with flow cytometry and enzyme-linked immunosorbent assay. In this study, platelets were first perfused through microfluidic channels capable of producing shear rates of 80 000-100 000 s-1 for exposure times of 0-73 ms. We investigated platelet activation by measuring the expression level of CD62P (soluble and surface expressed), platelet factor 4 (PF4), and beta-thromboglobulin (βTG). In addition, we measured potential platelet receptor shedding of GPVI and GPIb using flow cytometry. The results showed that a single pass to high shear with short exposure times (milliseconds) had no effect on the levels of CD62P, GPVI and GPIb, or on the release of alpha granule content (PF4, βTG, and sP-selectin).
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Affiliation(s)
- Nesreen Z Alsmadi
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas 75083, USA
| | - Sarah J Shapiro
- School of Chemical, Biological, and Materials Engineering, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Christopher S Lewis
- School of Chemical, Biological, and Materials Engineering, University of Oklahoma, Norman, Oklahoma 73019, USA
| | - Vinit M Sheth
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas 75083, USA
| | | | - David W Schmidtke
- Department of Bioengineering, University of Texas at Dallas, Richardson, Texas 75083, USA
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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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37
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Heilmann C, Trummer G, Beyersdorf F, Brehm K, Berchtold-Herz M, Schelling J, Geisen U, Zieger B. Acquired Von Willebrand syndrome in patients on long-term support with HeartMate II. Eur J Cardiothorac Surg 2017; 51:587-590. [PMID: 28082469 DOI: 10.1093/ejcts/ezw348] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 08/19/2016] [Indexed: 01/15/2023] Open
Abstract
Objectives Impaired binding of Von Willebrand factor (VWF) to platelets and to collagen due to acquired Von Willebrand syndrome (AVWS) is associated with support from a ventricular assist device (VAD) and can contribute to bleeding tendencies in patients with VADs. The onset of AVWS has been shown to occur immediately after VAD implantation. Our aim was to determine long-term data on AVWS in VAD patients. Methods We analysed 278 data sets of 74 patients on HeartMate II (HMII) support for 3-80 months after implantation (11.2 ± 12.1, median 6.3 months.). Ristocetin cofactor activity (VWF:RCo), collagen binding capacity (VWF:CB), VWF antigen (VWF:Ag) and the ratios of VWF:RCo/VWF:Ag and VWF:CB/VWF:Ag were determined. Further, the presence of high molecular weight (HMW) multimers of VWF was investigated. Results Abnormally low values of VWF:RCo/VWF:Ag and VWF:CB/VWF:Ag were found in 69% and 97% of blood samples, respectively. Only ten of 181 multimer analyses showed a normal pattern, and HMW multimers were present in both specimens in only one of the 74 patients. No significant changes in these parameters were observed over time. The VWF:CB/VWF:Ag ratio correlated with the multimer patterns, whereas the VWF:RCo/VWF:Ag ratio seemed to be less sensitive for AVWS. Conclusions Our data indicate that AVWS is a typical phenomenon in patients with VAD support and that there are no time-dependent changes in these parameters apparent in most patients on long-term support with HMII.
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Affiliation(s)
- Claudia Heilmann
- Department of Cardiovascular Surgery, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany
| | - Georg Trummer
- Department of Cardiovascular Surgery, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany
| | - Friedhelm Beyersdorf
- Department of Cardiovascular Surgery, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany
| | - Kerstin Brehm
- Department of Cardiovascular Surgery, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany
| | - Michael Berchtold-Herz
- Department of Cardiovascular Surgery, University Heart Center Freiburg-Bad Krozingen, Freiburg, Germany
| | - Johannes Schelling
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ulrich Geisen
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center Freiburg, Freiburg, Germany
| | - Barbara Zieger
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Identification of extant vertebrate Myxine glutinosa VWF: evolutionary conservation of primary hemostasis. Blood 2017; 130:2548-2558. [PMID: 28899852 DOI: 10.1182/blood-2017-02-770792] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Accepted: 08/23/2017] [Indexed: 11/20/2022] Open
Abstract
Hemostasis in vertebrates involves both a cellular and a protein component. Previous studies in jawless vertebrates (cyclostomes) suggest that the protein response, which involves thrombin-catalyzed conversion of a soluble plasma protein, fibrinogen, into a polymeric fibrin clot, is conserved in all vertebrates. However, similar data are lacking for the cellular response, which in gnathostomes is regulated by von Willebrand factor (VWF), a glycoprotein that mediates the adhesion of platelets to the subendothelial matrix of injured blood vessels. To gain evolutionary insights into the cellular phase of coagulation, we asked whether a functional vwf gene is present in the Atlantic hagfish, Myxine glutinosa We found a single vwf transcript that encodes a simpler protein compared with higher vertebrates, the most striking difference being the absence of an A3 domain, which otherwise binds collagen under high-flow conditions. Immunohistochemical analyses of hagfish tissues and blood revealed Vwf expression in endothelial cells and thrombocytes. Electron microscopic studies of hagfish tissues demonstrated the presence of Weibel-Palade bodies in the endothelium. Hagfish Vwf formed high-molecular-weight multimers in hagfish plasma and in stably transfected CHO cells. In functional assays, botrocetin promoted VWF-dependent thrombocyte aggregation. A search for vwf sequences in the genome of sea squirts, the closest invertebrate relatives of hagfish, failed to reveal evidence of an intact vwf gene. Together, our findings suggest that VWF evolved in the ancestral vertebrate following the divergence of the urochordates some 500 million years ago and that it acquired increasing complexity though sequential insertion of functional modules.
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Is Extracorporeal CO2 Removal Really “Safe” and “Less” Invasive? Observation of Blood Injury and Coagulation Impairment during ECCO2R. ASAIO J 2017; 63:666-671. [DOI: 10.1097/mat.0000000000000544] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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Brophy TM, Ward SE, McGimsey TR, Schneppenheim S, Drakeford C, O’Sullivan JM, Chion A, Budde U, O’Donnell JS. Plasmin Cleaves Von Willebrand Factor at K1491-R1492 in the A1–A2 Linker Region in a Shear- and Glycan-Dependent Manner In Vitro. Arterioscler Thromb Vasc Biol 2017; 37:845-855. [DOI: 10.1161/atvbaha.116.308524] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/23/2017] [Indexed: 12/20/2022]
Abstract
Objective—
Previous studies have demonstrated a role for plasmin in regulating plasma von Willebrand factor (VWF) multimer composition. Moreover, emerging data have shown that plasmin-induced cleavage of VWF is of particular importance in specific pathological states. Interestingly, plasmin has been successfully used as an alternative to ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif) in a mouse model of thrombotic thrombocytopenic purpura. Consequently, elucidating the molecular mechanisms through which plasmin binds and cleaves VWF is not only of basic scientific interest but also of direct clinical importance. Our aim was to investigate factors that modulate the susceptibility of human VWF to proteolysis by plasmin.
Approach and Results—
We have adapted the VWF vortex proteolysis assay to allow for time-dependent shear exposure studies. We show that globular VWF is resistant to plasmin cleavage under static conditions, but is readily cleaved by plasmin under shear. Although both plasmin and ADAMTS13 cleave VWF in a shear-dependent manner, plasmin does not cleave at the Tyr1605-Met1606 ADAMTS13 proteolytic site in the A2 domain. Rather under shear stress conditions, or in the presence of denaturants, such as urea or ristocetin, plasmin cleaves the K1491-R1492 peptide bond within the VWF A1–A2 linker region. Finally, we demonstrate that VWF susceptibility to plasmin proteolysis at K1491-R1492 is modulated by local N-linked glycan expression within A1A2A3, and specifically inhibited by heparin binding to the A1 domain.
Conclusions—
Improved understanding of the plasmin–VWF interaction offers exciting opportunities to develop novel adjunctive therapies for the treatment of refractory thrombotic thrombocytopenic purpura.
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Affiliation(s)
- Teresa M. Brophy
- From the Haemostasis Research Group, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St. James’s Hospital, Trinity College Dublin, Ireland (T.M.B., S.E.W., T.R.M.G., C.D., J.M.O., A.C., J.S.O.); Medilys Laborgesellschaft mbH, Department of Hämostaseology, Hamburg, Germany (S.S., U.B.); National Centre for Hereditary Coagulation Disorders, St. James’s Hospital, Dublin, Ireland (J.S.O.); and Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin (J.S.O.)
| | - Soracha E. Ward
- From the Haemostasis Research Group, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St. James’s Hospital, Trinity College Dublin, Ireland (T.M.B., S.E.W., T.R.M.G., C.D., J.M.O., A.C., J.S.O.); Medilys Laborgesellschaft mbH, Department of Hämostaseology, Hamburg, Germany (S.S., U.B.); National Centre for Hereditary Coagulation Disorders, St. James’s Hospital, Dublin, Ireland (J.S.O.); and Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin (J.S.O.)
| | - Thomas R. McGimsey
- From the Haemostasis Research Group, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St. James’s Hospital, Trinity College Dublin, Ireland (T.M.B., S.E.W., T.R.M.G., C.D., J.M.O., A.C., J.S.O.); Medilys Laborgesellschaft mbH, Department of Hämostaseology, Hamburg, Germany (S.S., U.B.); National Centre for Hereditary Coagulation Disorders, St. James’s Hospital, Dublin, Ireland (J.S.O.); and Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin (J.S.O.)
| | - Sonja Schneppenheim
- From the Haemostasis Research Group, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St. James’s Hospital, Trinity College Dublin, Ireland (T.M.B., S.E.W., T.R.M.G., C.D., J.M.O., A.C., J.S.O.); Medilys Laborgesellschaft mbH, Department of Hämostaseology, Hamburg, Germany (S.S., U.B.); National Centre for Hereditary Coagulation Disorders, St. James’s Hospital, Dublin, Ireland (J.S.O.); and Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin (J.S.O.)
| | - Clive Drakeford
- From the Haemostasis Research Group, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St. James’s Hospital, Trinity College Dublin, Ireland (T.M.B., S.E.W., T.R.M.G., C.D., J.M.O., A.C., J.S.O.); Medilys Laborgesellschaft mbH, Department of Hämostaseology, Hamburg, Germany (S.S., U.B.); National Centre for Hereditary Coagulation Disorders, St. James’s Hospital, Dublin, Ireland (J.S.O.); and Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin (J.S.O.)
| | - Jamie M. O’Sullivan
- From the Haemostasis Research Group, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St. James’s Hospital, Trinity College Dublin, Ireland (T.M.B., S.E.W., T.R.M.G., C.D., J.M.O., A.C., J.S.O.); Medilys Laborgesellschaft mbH, Department of Hämostaseology, Hamburg, Germany (S.S., U.B.); National Centre for Hereditary Coagulation Disorders, St. James’s Hospital, Dublin, Ireland (J.S.O.); and Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin (J.S.O.)
| | - Alain Chion
- From the Haemostasis Research Group, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St. James’s Hospital, Trinity College Dublin, Ireland (T.M.B., S.E.W., T.R.M.G., C.D., J.M.O., A.C., J.S.O.); Medilys Laborgesellschaft mbH, Department of Hämostaseology, Hamburg, Germany (S.S., U.B.); National Centre for Hereditary Coagulation Disorders, St. James’s Hospital, Dublin, Ireland (J.S.O.); and Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin (J.S.O.)
| | - Ulrich Budde
- From the Haemostasis Research Group, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St. James’s Hospital, Trinity College Dublin, Ireland (T.M.B., S.E.W., T.R.M.G., C.D., J.M.O., A.C., J.S.O.); Medilys Laborgesellschaft mbH, Department of Hämostaseology, Hamburg, Germany (S.S., U.B.); National Centre for Hereditary Coagulation Disorders, St. James’s Hospital, Dublin, Ireland (J.S.O.); and Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin (J.S.O.)
| | - James S. O’Donnell
- From the Haemostasis Research Group, Institute of Molecular Medicine, Trinity Centre for Health Sciences, St. James’s Hospital, Trinity College Dublin, Ireland (T.M.B., S.E.W., T.R.M.G., C.D., J.M.O., A.C., J.S.O.); Medilys Laborgesellschaft mbH, Department of Hämostaseology, Hamburg, Germany (S.S., U.B.); National Centre for Hereditary Coagulation Disorders, St. James’s Hospital, Dublin, Ireland (J.S.O.); and Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin (J.S.O.)
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Feldmann C, Zayat R, Goetzenich A, Aljalloud A, Woelke E, Maas J, Tewarie L, Schmitz-Rode T, Autschbach R, Steinseifer U, Moza A. Perioperative onset of acquired von Willebrand syndrome: Comparison between HVAD, HeartMate II and on-pump coronary bypass surgery. PLoS One 2017; 12:e0171029. [PMID: 28234916 PMCID: PMC5325196 DOI: 10.1371/journal.pone.0171029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/13/2017] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Acquired von Willebrand syndrome (AvWS) is associated with postoperative bleeding complications in patients with continuous flow left ventricular assist devices (CF-LVADs). The aim of this study is to analyze the perioperative vWF profile comparing an axial pump (HMII) to a centrifugal pump (HVAD) regarding the correlation between perioperative occurrence of AvWS, early- and late-postoperative bleeding events. METHODS From July 2013 until March 2015 blood samples of 33 patients (12 HMII/ 8 HVAD/ 13 controls) were prospectively collected at 12 different time points and analyzed for the vWF antigen (vWF:Ag), its activity (vWF:Ac) and the vWF:Ac/vWF:Ag-ratio (vWF:ratio). The follow up period for postoperative bleeding events was from July 2013 until July 2016. RESULTS Postoperatively, there was no difference in the vWF-profile between HVAD and HMII groups. However, a subgroup of patients already had significantly lower vWF:ratios preoperatively. Postoperatively, both CF-LVAD groups presented significantly lower vWF:ratios compared to the control group. Bleeding events per patient-year did not differ between the two groups (HMII vs. HVAD: 0.67 vs. 0.85, p = 0.685). We detected a correlation between vWF:ratio <0.7at LVAD-start (r = -0.583, p = 0.006) or at the end of surgery (r = -0.461, p = 0.035) and the occurrence of pericardial tamponade. In the control group, the drop in both vWF:Ag and vWF:Ac recovered immediately postoperatively above preoperative values. CONCLUSION A subgroup of patients with end-stage heart failure already suffers AvWS preoperatively. In both CF-LVAD groups, AvWS begins immediately after surgery. Intraoperative vWF:ratios <0.7 correlate with higher incidences of pericardial tamponade and re-operation. The presumably dilutive effect of the heart lung machine on vWF vanishes immediately at the end of surgery, possibly as part of an acute-phase response.
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Affiliation(s)
- Christina Feldmann
- Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany
| | - Rashad Zayat
- Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany
- * E-mail:
| | - Andreas Goetzenich
- Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany
| | - Ali Aljalloud
- Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany
| | - Eva Woelke
- Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany
| | - Judith Maas
- Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany
| | - Lachmandath Tewarie
- Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany
| | - Thomas Schmitz-Rode
- Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany
| | - Ruediger Autschbach
- Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany
| | - Ulrich Steinseifer
- Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany
| | - Ajay Moza
- Department of Thoracic and Cardiovascular Surgery, University Hospital RWTH Aachen, Aachen, Germany
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Aponte-Santamaría C, Lippok S, Mittag JJ, Obser T, Schneppenheim R, Baldauf C, Gräter F, Budde U, Rädler JO. Mutation G1629E Increases von Willebrand Factor Cleavage via a Cooperative Destabilization Mechanism. Biophys J 2017; 112:57-65. [PMID: 28076816 PMCID: PMC5232862 DOI: 10.1016/j.bpj.2016.11.3202] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 11/12/2016] [Accepted: 11/30/2016] [Indexed: 02/04/2023] Open
Abstract
The large multimeric glycoprotein von Willebrand Factor (VWF) plays a pivotal adhesive role during primary hemostasis. VWF is cleaved by the protease ADAMTS13 as a down-regulatory mechanism to prevent excessive VWF-mediated platelet aggregation. For each VWF monomer, the ADAMTS13 cleavage site is located deeply buried inside the VWF A2 domain. External forces in vivo or denaturants in vitro trigger the unfolding of this domain, thereby leaving the cleavage site solvent-exposed and ready for cleavage. Mutations in the VWF A2 domain, facilitating the cleavage process, cause a distinct form of von Willebrand disease (VWD), VWD type 2A. In particular, the VWD type 2A Gly1629Glu mutation drastically accelerates the proteolytic cleavage activity, even in the absence of forces or denaturants. However, the effect of this mutation has not yet been quantified, in terms of kinetics or thermodynamics, nor has the underlying molecular mechanism been revealed. In this study, we addressed these questions by using fluorescence correlation spectroscopy, molecular dynamics simulations, and free energy calculations. The measured enzyme kinetics revealed a 20-fold increase in the cleavage rate for the Gly1629Glu mutant compared with the wild-type VWF. Cleavage was found cooperative with a cooperativity coefficient n = 2.3, suggesting that the mutant VWF gives access to multiple cleavage sites of the VWF multimer at the same time. According to our simulations and free energy calculations, the Gly1629Glu mutation causes structural perturbation in the A2 domain and thereby destabilizes the domain by ∼10 kJ/mol, promoting its unfolding. Taken together, the enhanced proteolytic activity of Gly1629Glu can be readily explained by an increased availability of the ADAMTS13 cleavage site through A2-domain-fold thermodynamic destabilization. Our study puts forward the Gly1629Glu mutant as a very efficient enzyme substrate for ADAMTS13 activity assays.
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Affiliation(s)
- Camilo Aponte-Santamaría
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany; Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg, Germany.
| | - Svenja Lippok
- Faculty of Physics and Center for NanoScience, Ludwig Maximilian University, Munich, Germany
| | - Judith J Mittag
- Faculty of Physics and Center for NanoScience, Ludwig Maximilian University, Munich, Germany
| | - Tobias Obser
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Reinhard Schneppenheim
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carsten Baldauf
- Theory Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
| | - Frauke Gräter
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany; Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg, Germany
| | - Ulrich Budde
- Medilys Coagulation Laboratory, Asklepios Klinic Altona, Hamburg, Germany
| | - Joachim O Rädler
- Faculty of Physics and Center for NanoScience, Ludwig Maximilian University, Munich, Germany
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Lippok S, Radtke M, Obser T, Kleemeier L, Schneppenheim R, Budde U, Netz RR, Rädler JO. Shear-Induced Unfolding and Enzymatic Cleavage of Full-Length VWF Multimers. Biophys J 2017; 110:545-554. [PMID: 26840720 DOI: 10.1016/j.bpj.2015.12.023] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 11/23/2015] [Accepted: 12/17/2015] [Indexed: 10/22/2022] Open
Abstract
Proteolysis of the multimeric blood coagulation protein von Willebrand Factor (VWF) by ADAMTS13 is crucial for prevention of microvascular thrombosis. ADAMTS13 cleaves VWF within the mechanosensitive A2 domain, which is believed to open under shear flow. In this study, we combine fluorescence correlation spectroscopy (FCS) and a microfluidic shear cell to monitor real-time kinetics of full-length VWF proteolysis as a function of shear stress. For comparison, we also measure the Michaelis-Menten kinetics of ADAMTS13 cleavage of wild-type VWF in the absence of shear but partially denaturing conditions. Under shear, ADAMTS13 activity on full-length VWF arises without denaturing agent as evidenced by FCS and gel-based multimer analysis. In agreement with Brownian hydrodynamics simulations, we find a sigmoidal increase of the enzymatic rate as a function of shear at a threshold shear rate γ˙1/2 = 5522/s. The same flow-rate dependence of ADAMTS13 activity we also observe in blood plasma, which is relevant to predict hemostatic dysfunction.
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Affiliation(s)
- Svenja Lippok
- Faculty of Physics and Center for NanoScience, Ludwig Maximilian University, Munich, Germany
| | - Matthias Radtke
- Department of Physics, Freie Universität Berlin, Berlin, Germany
| | - Tobias Obser
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lars Kleemeier
- Faculty of Physics and Center for NanoScience, Ludwig Maximilian University, Munich, Germany
| | - Reinhard Schneppenheim
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ulrich Budde
- Coagulation Lab, Medilys Laborgesellschaft Hamburg, Hamburg, Germany
| | - Roland R Netz
- Department of Physics, Freie Universität Berlin, Berlin, Germany
| | - Joachim O Rädler
- Faculty of Physics and Center for NanoScience, Ludwig Maximilian University, Munich, Germany.
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Posch S, Aponte-Santamaría C, Schwarzl R, Karner A, Radtke M, Gräter F, Obser T, König G, Brehm MA, Gruber HJ, Netz RR, Baldauf C, Schneppenheim R, Tampé R, Hinterdorfer P. Mutual A domain interactions in the force sensing protein von Willebrand factor. J Struct Biol 2017; 197:57-64. [PMID: 27113902 DOI: 10.1016/j.jsb.2016.04.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 01/21/2023]
Abstract
The von Willebrand factor (VWF) is a glycoprotein in the blood that plays a central role in hemostasis. Among other functions, VWF is responsible for platelet adhesion at sites of injury via its A1 domain. Its adjacent VWF domain A2 exposes a cleavage site under shear to degrade long VWF fibers in order to prevent thrombosis. Recently, it has been shown that VWF A1/A2 interactions inhibit the binding of platelets to VWF domain A1 in a force-dependent manner prior to A2 cleavage. However, whether and how this interaction also takes place in longer VWF fragments as well as the strength of this interaction in the light of typical elongation forces imposed by the shear flow of blood remained elusive. Here, we addressed these questions by using single molecule force spectroscopy (SMFS), Brownian dynamics (BD), and molecular dynamics (MD) simulations. Our SMFS measurements demonstrate that the A2 domain has the ability to bind not only to single A1 domains but also to VWF A1A2 fragments. SMFS experiments of a mutant [A2] domain, containing a disulfide bond which stabilizes the domain against unfolding, enhanced A1 binding. This observation suggests that the mutant adopts a more stable conformation for binding to A1. We found intermolecular A1/A2 interactions to be preferred over intramolecular A1/A2 interactions. Our data are also consistent with the existence of two cooperatively acting binding sites for A2 in the A1 domain. Our SMFS measurements revealed a slip-bond behavior for the A1/A2 interaction and their lifetimes were estimated for forces acting on VWF multimers at physiological shear rates using BD simulations. Complementary fitting of AFM rupture forces in the MD simulation range adequately reproduced the force response of the A1/A2 complex spanning a wide range of loading rates. In conclusion, we here characterized the auto-inhibitory mechanism of the intramolecular A1/A2 bond as a shear dependent safeguard of VWF, which prevents the interaction of VWF with platelets.
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Affiliation(s)
- Sandra Posch
- Department of Applied Experimental Biophysics, Institute of Biophysics, Johannes Kepler University, Linz, Austria
| | | | | | - Andreas Karner
- Center for Advanced Bioanalysis GmbH (CBL), Linz, Austria
| | | | - Frauke Gräter
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Tobias Obser
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Gesa König
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Maria A Brehm
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Hermann J Gruber
- Department of Applied Experimental Biophysics, Institute of Biophysics, Johannes Kepler University, Linz, Austria
| | | | - Carsten Baldauf
- Theory Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
| | - Reinhard Schneppenheim
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Frankfurt/Main, Germany
| | - Peter Hinterdorfer
- Department of Applied Experimental Biophysics, Institute of Biophysics, Johannes Kepler University, Linz, Austria; Center for Advanced Bioanalysis GmbH (CBL), Linz, Austria.
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Lukito P, Wong A, Jing J, Arthur JF, Marasco SF, Murphy DA, Bergin PJ, Shaw JA, Collecutt M, Andrews RK, Gardiner EE, Davis AK. Mechanical circulatory support is associated with loss of platelet receptors glycoprotein Ibα and glycoprotein VI. J Thromb Haemost 2016; 14:2253-2260. [PMID: 27601054 DOI: 10.1111/jth.13497] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/22/2016] [Indexed: 11/25/2022]
Abstract
Essentials Relationship of acquired von Willebrand disease (VWD) and platelet dysfunction is explored. Patients with ventricular assist devices and on extracorporeal membrane oxygenation are investigated. Acquired VWD and platelet receptor shedding is demonstrated in the majority of patients. Loss of platelet adhesion receptors glycoprotein (GP) Ibα and GPVI may increase bleeding risk. SUMMARY Background Ventricular assist devices (VADs) and extracorporeal membrane oxygenation (ECMO) are associated with bleeding that is not fully explained by anticoagulant or antiplatelet use. Exposure of platelets to elevated shear in vitro leads to increased shedding. Objectives To investigate whether loss of platelet receptors occurs in vivo, and the relationship with acquired von Willebrand syndrome (AVWS). Methods Platelet counts, coagulation tests and von Willebrand factor (VWF) analyses were performed on samples from 21 continuous flow VAD (CF-VAD), 20 ECMO, 12 heart failure and seven aortic stenosis patients. Levels of platelet receptors were measured by flow cytometry or ELISA. Results The loss of high molecular weight VWF multimers was observed in 18 of 19 CF-VAD and 14 of 20 ECMO patients, consistent with AVWS. Platelet receptor shedding was demonstrated by elevated soluble glycoprotein (GP) VI levels in plasma and significantly reduced surface GPIbα and GPVI levels in CF-VAD and ECMO patients as compared with healthy donors. Platelet receptor levels were also significantly reduced in heart failure patients. Conclusions These data link AVWS and increased platelet receptor shedding in patients with CF-VADs or ECMO for the first time. Loss of the platelet surface receptors GPIbα and GPVI in heart failure, CF-VAD and ECMO patients may contribute to ablated platelet adhesion/activation, and limit thrombus formation under high/pathologic shear conditions.
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Affiliation(s)
- P Lukito
- Haematology Unit, Alfred Hospital, Melbourne, Australia
| | - A Wong
- Haematology Unit, Alfred Hospital, Melbourne, Australia
| | - J Jing
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - J F Arthur
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - S F Marasco
- Cardiothoracic Unit, Alfred Hospital, Melbourne, Australia
| | - D A Murphy
- Intensive Care Unit, Alfred Hospital, Melbourne, Australia
| | - P J Bergin
- Cardiology Unit, Alfred Hospital, Melbourne, Australia
| | - J A Shaw
- Cardiology Unit, Alfred Hospital, Melbourne, Australia
| | - M Collecutt
- Haematology Laboratory, Alfred Hospital, Melbourne, Australia
| | - R K Andrews
- Australian Centre for Blood Diseases, Monash University, Melbourne, Australia
| | - E E Gardiner
- Department of Cancer Biology and Therapeutics, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - A K Davis
- Haematology Unit, Alfred Hospital, Melbourne, Australia
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Stauch T, Dreuw A. Advances in Quantum Mechanochemistry: Electronic Structure Methods and Force Analysis. Chem Rev 2016; 116:14137-14180. [PMID: 27767298 DOI: 10.1021/acs.chemrev.6b00458] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In quantum mechanochemistry, quantum chemical methods are used to describe molecules under the influence of an external force. The calculation of geometries, energies, transition states, reaction rates, and spectroscopic properties of molecules on the force-modified potential energy surfaces is the key to gain an in-depth understanding of mechanochemical processes at the molecular level. In this review, we present recent advances in the field of quantum mechanochemistry and introduce the quantum chemical methods used to calculate the properties of molecules under an external force. We place special emphasis on quantum chemical force analysis tools, which can be used to identify the mechanochemically relevant degrees of freedom in a deformed molecule, and spotlight selected applications of quantum mechanochemical methods to point out their synergistic relationship with experiments.
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Affiliation(s)
- Tim Stauch
- Interdisciplinary Center for Scientific Computing , Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing , Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
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Obser T, Ledford-Kraemer M, Oyen F, Brehm MA, Denis CV, Marschalek R, Montgomery RR, Sadler JE, Schneppenheim S, Budde U, Schneppenheim R. Identification and characterization of the elusive mutation causing the historical von Willebrand Disease type IIC Miami. J Thromb Haemost 2016; 14:1725-35. [PMID: 27344059 PMCID: PMC5035592 DOI: 10.1111/jth.13398] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 06/15/2016] [Indexed: 11/28/2022]
Abstract
UNLABELLED Essentials Von Willebrand disease IIC Miami features high von Willebrand factor (VWF) with reduced function. We aimed to identify and characterize the elusive underlying mutation in the original family. An inframe duplication of VWF exons 9-10 was identified and characterized. The mutation causes a defect in VWF multimerization and decreased VWF clearance from the circulation. SUMMARY Background A variant of von Willebrand disease (VWD) type 2A, phenotype IIC (VWD2AIIC), is characterized by recessive inheritance, low von Willebrand factor antigen (VWF:Ag), lack of VWF high-molecular-weight multimers, absence of VWF proteolytic fragments and mutations in the VWF propeptide. A family with dominantly inherited VWD2AIIC but markedly elevated VWF:Ag of > 2 U L(-1) was described as VWD type IIC Miami (VWD2AIIC-Miami) in 1993; however, the molecular defect remained elusive. Objectives To identify the molecular mechanism underlying the phenotype of the original VWD2AIIC-Miami. Patients and Methods We studied the original family with VWD2AIIC-Miami phenotypically and by genotyping. The identified mutation was recombinantly expressed and characterized by standard techniques, confocal imaging and in a mouse model, respectively. Results By Multiplex ligation-dependent probe amplification we identified an in-frame duplication of VWF exons 9-10 (c.998_1156dup; p.Glu333_385dup) in all patients. Recombinant mutant (rm)VWF only presented as a dimer. Co-expressed with wild-type VWF, the multimer pattern was indistinguishable from patients' plasma VWF. Immunofluorescence studies indicated retention of rmVWF in unusually large intracellular granules in the endoplasmic reticulum. ADAMTS-13 proteolysis of rmVWF under denaturing conditions was normal; however, an aberrant proteolytic fragment was apparent. A decreased ratio of VWF propeptide to VWF:Ag and a 1-desamino-8-d-arginine vasopressin (DDAVP) test in one patient indicated delayed VWF clearance, which was supported by clearance data after infusion of rmVWF into VWF(-/-) mice. Conclusion The unique phenotype of VWD2 type IIC-Miami results from dominant impairment of multimer assembly, an aberrant structure of mutant mature VWF and reduced clearance in vivo.
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Affiliation(s)
- T Obser
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - F Oyen
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - M A Brehm
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - C V Denis
- INSERM UMR_S 1176, Université Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicetre, France
| | - R Marschalek
- Institute of Pharmaceutical Biology/ZAFES/DCAL, Biocenter, Johann-Wolfgang-Goethe-University Frankfurt, Frankfurt/Main, Germany
| | - R R Montgomery
- Blood Research Institute of Blood Center of Wisconsin and Medical College of Wisconsin, Milwaukee, WI, USA
| | - J E Sadler
- Departments of Medicine and Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, USA
| | - S Schneppenheim
- Medilys Central Laboratory Coagulation, Asklepios Clinic Altona, Hamburg, Germany
| | - U Budde
- Medilys Central Laboratory Coagulation, Asklepios Clinic Altona, Hamburg, Germany
| | - R Schneppenheim
- Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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N-linked glycans within the A2 domain of von Willebrand factor modulate macrophage-mediated clearance. Blood 2016; 128:1959-1968. [PMID: 27554083 DOI: 10.1182/blood-2016-04-709436] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 08/16/2016] [Indexed: 12/11/2022] Open
Abstract
Enhanced von Willebrand factor (VWF) clearance is important in the etiology of von Willebrand disease. However, the molecular mechanisms underlying VWF clearance remain poorly understood. In this study, we investigated the role of VWF domains and specific glycan moieties in regulating in vivo clearance. Our findings demonstrate that the A1 domain of VWF contains a receptor-recognition site that plays a key role in regulating the interaction of VWF with macrophages. In A1-A2-A3 and full-length VWF, this macrophage-binding site is cryptic but becomes exposed following exposure to shear or ristocetin. Previous studies have demonstrated that the N-linked glycans within the A2 domain play an important role in modulating susceptibility to ADAMTS13 proteolysis. We further demonstrate that these glycans presented at N1515 and N1574 also play a critical role in protecting VWF against macrophage binding and clearance. Indeed, loss of the N-glycan at N1515 resulted in markedly enhanced VWF clearance that was significantly faster than that observed with any previously described VWF mutations. In addition, A1-A2-A3 fragments containing the N1515Q or N1574Q substitutions also demonstrated significantly enhanced clearance. Importantly, clodronate-induced macrophage depletion significantly attenuated the increased clearance observed with N1515Q and N1574Q in both full-length VWF and A1-A2-A3. Finally, we further demonstrate that loss of these N-linked glycans does not enhance clearance in VWF in the presence of a structurally constrained A2 domain. Collectively, these novel findings support the hypothesis that conformation of the VWF A domains plays a critical role in modulating macrophage-mediated clearance of VWF in vivo.
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Zhong H, Zhu Z, Tang J. von Willebrand factor and bleeding complication in patients treated with intra-aortic balloon pump. Int J Cardiol 2016; 214:482. [PMID: 27100338 DOI: 10.1016/j.ijcard.2016.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 04/02/2016] [Indexed: 10/22/2022]
Affiliation(s)
- Hua Zhong
- Department of Cardiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Zhaowei Zhu
- Department of Cardiology, Second Xiangya Hospital of Central South University, Changsha, China
| | - Jianjun Tang
- Department of Cardiology, Second Xiangya Hospital of Central South University, Changsha, China.
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50
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Gastrointestinal Bleeding Following LVAD Placement from Top to Bottom. Dig Dis Sci 2016; 61:1440-7. [PMID: 27017225 PMCID: PMC4875872 DOI: 10.1007/s10620-016-4123-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 03/06/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Left ventricular assist devices (LVADs) are an increasingly prevalent form of mechanical support for patients with end-stage heart failure. These devices can be implanted both as a bridge to transplant and as definitive/destination therapy. Gastrointestinal (GI) bleeding is one of the most common and recalcitrant long-term complications following LVAD implantation, with an incidence approaching 30 %. AIMS This review will discuss what is known about the pathophysiology of GI bleeding in LVADs and the currently available options for medical and/or endoscopic management. RESULTS The pathophysiology of bleeding is multifactorial, with hemodynamic alterations, acquired von Willebrand factor deficiency, and coagulopathy being most often implicated. The majority of bleeding events in this population result from angioectasias and gastroduodenal erosive disease. While these bleeding events are significant and often require transfusion therapy, they are rarely life threatening. Endoscopy remains the standard of care with upper endoscopy offering the highest diagnostic yield in these patients. However, the effectiveness of endoscopic hemostasis in this population is not well established. A small number of studies have evaluated medical therapy and alterations in LVAD settings as a means of preventing or treating bleeding with variable results. CONCLUSIONS In summary, GI bleeding with LVADs is a common occurrence and will continue to be as more LVADs are being performed for destination therapy.
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