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Seidizadeh O, Mollica L, Zambarbieri S, Baronciani L, Cairo A, Colpani P, Cozzi G, Pagliari MT, Ciavarella A, Siboni SM, Peyvandi F. Type 2M/2A von Willebrand disease: a shared phenotype between type 2M and 2A. Blood Adv 2024; 8:1725-1736. [PMID: 38315875 PMCID: PMC10997909 DOI: 10.1182/bloodadvances.2024012626] [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: 01/10/2024] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 02/07/2024] Open
Abstract
ABSTRACT Four variants have been continuously subjected to debate and received different von Willebrand disease (VWD) classifications: p.R1315L, p.R1315C, p.R1374H, and p.R1374C. We chose to comprehensively investigate these variants with full set of VWD tests, protein-modeling predictions and applying structural biology. Patients with p.R1315L, p.R1315C, p.R1374H, and p.R1374C were included. A group with type 2A and 2M was included to better understand similarities and differences. Patients were investigated for phenotypic assays and underlying disease mechanisms. We applied deep protein modeling predictions and structural biology to elucidate the causative effects of variants. Forty-three patients with these variants and 70 with 2A (n = 35) or 2M (n = 35) were studied. Patients with p.R1315L, p.R1374H, or p.R1374C showed a common phenotype between 2M and 2A using von Willebrand factor (VWF):GPIbR/VWF:Ag and VWF:CB/VWF:Ag ratios and VWF multimeric profile, whereas p.R1315C represented a type 2M phenotype. There was an overall reduced VWF synthesis or secretion in 2M and cases with p.R1315L, p.R1374H, and p.R1374C, but not in 2A. Reduced VWF survival was observed in most 2A (77%), 2M (80%), and all 40 cases with p.R1315L, p.R1374H, and p.R1374C. These were the only variants that fall at the interface between the A1-A2 domains. p.R1315L/C mutants induce more compactness and internal mobility, whereas p.R1374H/C display a more extended overall geometry. We propose a new classification of type 2M/2A for p.R1315L, p.R1374H, and p.R1374C because they share a common phenotype with 2M and 2A. Our structural analysis shows the unique location of these variants on the A1-A2 domains and their distinctive effect on VWF.
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Affiliation(s)
- Omid Seidizadeh
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
| | - Luca Mollica
- Department of Medical Biotechnologies and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Serena Zambarbieri
- Department of Medical Biotechnologies and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Luciano Baronciani
- Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan, Italy
| | - Andrea Cairo
- Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan, Italy
| | - Paola Colpani
- Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan, Italy
| | - Giovanna Cozzi
- Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan, Italy
| | - Maria Teresa Pagliari
- Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan, Italy
| | - Alessandro Ciavarella
- Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan, Italy
| | - Simona M. Siboni
- Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan, Italy
| | - Flora Peyvandi
- Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
- Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Milan, Italy
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Ramesh P, Kanagalingam S, Zargham Ul Haq FNU, Victory Srinivasan N, Khan AI, Mashat GD, Hazique M, Khan KI, Khan S. Acquired Von Willebrand Deficiency in Adults With Aortic Stenosis: A Systematic Review. Cureus 2022; 14:e28879. [PMID: 36225403 PMCID: PMC9541123 DOI: 10.7759/cureus.28879] [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: 08/11/2022] [Accepted: 09/07/2022] [Indexed: 11/16/2022] Open
Abstract
Von Willebrand factor (VWF) deficiency is associated with bleeding complications. The congenital type of Von Willebrand disease(VWD) is a very well-known bleeding disorder and sometimes may be associated with life-threatening hemorrhage. This systematic review is aimed at gathering further knowledge regarding the pathology of an acquired VWD form within a population of patients with aortic stenosis (AS) by shortlisting quality articles on this theme, through the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) 2020 guidelines. High shear stress caused by the stenotic valve cleaves VWF multimers, causing a relative state of deficiency. The condition returns to baseline immediately following surgical replacement of the valve. Results across eight studies reviewed by a majority concluded that in an AS patient with bleeding, the most likely cause is an acquired deficiency of VWF, associated with factors influencing blood flow and caused by the in-situ valve. However, several studies suggested otherwise/were misclassifications. This review highlighted the relationship between AS and acquired VWF deficiency and should be foreseen as an adverse complication, attracting further research and future theragnostic strategies for this condition.
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Ortiz-Otero N, Marshall JR, Lash BW, King MR. Platelet mediated TRAIL delivery for efficiently targeting circulating tumor cells. NANOSCALE ADVANCES 2020; 2:3942-3953. [PMID: 36132797 PMCID: PMC9419179 DOI: 10.1039/d0na00271b] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 07/22/2020] [Indexed: 05/09/2023]
Abstract
Several studies have demonstrated the role of platelets in promoting cancer metastasis. Platelets bind to and protect circulating tumor cells (CTCs) from hemodynamic forces and immune cells, and also promote tumor cell arrest in the vasculature and extravasation. Thus, platelets represent a promising vehicle to deliver anticancer therapeutic agents to CTCs. In this study, we developed a novel platelet-mediated TNF-related apoptosis inducing ligand (TRAIL) delivery system to target CTCs and hinder metastasis via "in situ" platelet modification. This platelet-mediated TRAIL delivery significantly reduced the viability of colorectal and breast cancer cells circulating in flowing blood under physiological shear conditions. TRAIL-coated platelets significantly killed over 60% of CTCs in flowing blood from a variety of primary metastatic cancer samples. Platelets have been considered an important player in the regulation of metastasis due to their interaction with cancer cells in the circulation; the current study supports the idea of using platelet-based TRAIL delivery as a promising CTC-targeted cancer therapy.
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Affiliation(s)
- Nerymar Ortiz-Otero
- Meinig School of Biomedical Engineering, Cornell University Ithaca NY 14850 USA
| | - Jocelyn R Marshall
- Meinig School of Biomedical Engineering, Cornell University Ithaca NY 14850 USA
| | | | - Michael R King
- Department of Biomedical Engineering, Vanderbilt University Nashville TN 37202 USA
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Case report of two siblings with type 2A von Willebrand disease involving a novel mutation within the calcium-binding site of the A2 domain of von Willebrand factor. Blood Coagul Fibrinolysis 2019; 30:161-167. [DOI: 10.1097/mbc.0000000000000798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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5
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Novel insights into the clinical phenotype and pathophysiology underlying low VWF levels. Blood 2017; 130:2344-2353. [PMID: 28916584 DOI: 10.1182/blood-2017-05-786699] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Accepted: 09/01/2017] [Indexed: 11/20/2022] Open
Abstract
Critical clinical questions remain unanswered regarding diagnosis and management of patients with low von Willebrand factor (VWF) levels (30-50 IU/dL). To address these questions, the Low VWF Ireland Cohort (LoVIC) study investigated 126 patients registered with low VWF levels. Despite marginally reduced plasma VWF levels, International Society of Thrombosis and Haemostasis Bleeding Assessment Tool (ISTH BAT) confirmed significant bleeding phenotypes in the majority of LoVIC patients. Importantly, bleeding tendency did not correlate with plasma VWF levels within the 30 to 50 IU/dL range. Furthermore, bleeding phenotypes could not be explained by concurrent hemostatic defects. Plasma factor VIII to VWF antigen (VWF:Ag) ratios were significantly increased in LoVIC patients compared with controls (P < .0001). In contrast, VWF propeptide to VWF:Ag ratios >3 were observed in only 6% of the LoVIC cohort. Furthermore, platelet-VWF collagen binding activity levels were both significantly reduced compared with controls (P < .05). In response to 1-desamino-8-D-arginine vasopressin (DDAVP), peak VWF:Ag levels exceeded 100 IU/dL in 88% of patients and was sustained >100 IU/dL after 4 hours in 72% of subjects. In conclusion, our novel data suggest that low VWF levels can be associated with significant bleeding and are predominantly due to reductions in VWF synthesis and/or constitutive secretion. Although enhanced VWF clearance may contribute to the pathophysiology in some individuals, the absolute reduction in VWF plasma half-life is usually mild and not sufficient to significantly impact upon the duration of DDAVP-induced VWF response. This trial was registered at www.clinicaltrials.gov as #NCT03167320.
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Zhou YF, Eng ET, Zhu J, Lu C, Walz T, Springer TA. Sequence and structure relationships within von Willebrand factor. Blood 2012; 120:449-58. [PMID: 22490677 PMCID: PMC3398765 DOI: 10.1182/blood-2012-01-405134] [Citation(s) in RCA: 203] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 03/24/2012] [Indexed: 11/20/2022] Open
Abstract
In the present study, we re-annotated von Willebrand factor (VWF), assigned its entire sequence to specific modules, and related these modules to structure using electron microscopy (EM). The D domains are assemblies of smaller modules visible as lobes in EM. Modules in the D-domain assemblies include von Willebrand D, 8-cysteine, trypsin inhibitor-like, E or fibronectin type 1-like domains, and a unique D4N module in D4. The D1-D2 prodomain shows 2 large connected assemblies, each containing smaller lobes. The previous B and C regions of VWF are re-annotated as 6 tandem von Willebrand C (VWC) and VWC-like domains. These 6 VWC domains correspond to 6 elongated domains that associate in pairs at acidic pH in the stem region of VWF dimeric bouquets. This correspondence is demonstrated by binding of integrin α(IIb)β(3) to the fourth module seen in EM, VWC4, which bears the VWF Arg-Gly-Asp motif. The C-terminal cystine knot domain dimerizes end-to-end in a manner predicted by homology to TGF-β and orients approximately perpendicular to the VWC domains in dimeric bouquets. Homologies of domains in VWF to domains in other proteins allow many disulfide bonds to be tentatively assigned, which may have functional implications.
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Affiliation(s)
- Yan-Feng Zhou
- Department of Biological Chemistry and Molecular Pharmacology, Immune Disease Institute and Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
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Mohl A, Boda Z, Jager R, Losonczy H, Marosi A, Masszi T, Nagy E, Nemes L, Obser T, Oyen F, Radványi G, Schlammadinger Á, Szélessy ZS, Várkonyi A, Vezendy K, Vilimi B, Schneppenheim R, Bodó I. Common large partial VWF gene deletion does not cause alloantibody formation in the Hungarian type 3 von Willebrand disease population. J Thromb Haemost 2011; 9:945-52. [PMID: 21362127 DOI: 10.1111/j.1538-7836.2011.04250.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Type 3 von Willebrand disease (VWD) is an autosomal recessive bleeding disorder, characterized by virtually undetectable plasma von Willebrand factor (VWF) and consequently reduced plasma factor VIII levels. Genetic mutations responsible for type 3 VWD are very heterogeneous, scattered throughout the VWF gene and show high variability among different populations. METHODS Twenty-five severe VWD patients were studied by direct sequencing of the 51 coding exons of the VWF gene. The total number of VWD type 3 families in Hungary is 24, of which 23 were investigated. RESULTS Fifteen novel mutations were identified in 31 alleles, five being nonsense mutations (p.Q1238X, p.Q1898X, p.Q1931X, p.S2505X and p.S2568X), four small deletions and insertions resulting in frame shifts (c.1992insC, c.3622delT, c.5315insGA and c.7333delG), one a large partial deletion (delExon1-3) of the 5'-region, four candidate missense mutations (p.C35R, p.R81G, p.C295S, p.C623T) and one a candidate splice site mutation (c.1730-10C>A). Six previously described mutations were detected in 17 alleles, including the repeatedly found c.2435delC, p.R1659X and p.R1853X. Only one patient developed alloantibodies to VWF, carrying a homozygous c.3622delT. CONCLUSION We report the genetic background of the entire Hungarian type 3 VWD population. A large novel deletion, most probably due to a founder effect, seems to be unique to Hungarian type 3 VWD patients with high allele frequency. In contrast to previous reports, none of the five patients homozygous for the large partial deletion developed inhibitors to VWF. This discrepancy raises the possibility of selection bias in some of the reports.
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Affiliation(s)
- A Mohl
- 2nd Department of Pediatrics, Semmelweis University, Budapest, Hungary
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Veyradier A, Caron C, Ternisien C, Wolf M, Trossaert M, Fressinaud E, Goudemand J. Validation of the first commercial ELISA for type 2N von Willebrand's disease diagnosis. Haemophilia 2011; 17:944-51. [PMID: 21371195 DOI: 10.1111/j.1365-2516.2011.02499.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Type 2N von Willebrand's disease (VWD) is characterized by a factor VIII (FVIII) deficiency and a low FVIII/VWF ratio related to a markedly decreased affinity of von Willebrand factor (VWF) to FVIII. Type 2N VWD is diagnosed using assays allowing the measurement of plasma VWF capacity to bind FVIII (VWF:FVIIIB). These assays, crucial in order to distinguish type 2N VWD patients from mild haemophiliacs A and haemophilia A carriers, remain exclusively homemade and limited to laboratories possessing a high level of expertise in VWD. We evaluated the first commercial ELISA (Asserachrom® VWF:FVIIIB; Stago) comparated to a reference method in a multicentric study involving 205 subjects: 60 healthy volunteers, 37 haemophiliacs A, 17 haemophilia A carriers, 37 patients with type 2N VWD, 9 heterozygous carriers for a 2N mutation and 45 patients with miscellaneous other types of VWD (all previously characterized). A diluted plasma sample adjusted to 10 IU dL(-1) of VWF:Ag was incubated with a rabbit antihuman VWF polyclonal antibody. After removing the endogenous FVIII, recombinant FVIII (rFVIII) was added and bound rFVIII was quantified using a peroxydase-conjugated mouse antihuman FVIII monoclonal antibody. The intra-assay and inter-assay reproducibility was satisfactory. In all subgroups, both methods were well correlated. All type 2N VWD patients exhibited a markedly decreased VWF:FVIIIB (lower than 15%) and all heterozygous 2N carriers had a moderately decreased VWF:FVIIIB (between 30% and 65%). All controls (healthy subjects, haemophiliacs A and haemophilia A carriers) had a normal VWF:FVIIIB (higher than 80%) except one healthy volunteer and three haemophiliacs who exhibited a moderately decreased VWF:FVIIIB suggesting a heterozygous status for a 2N mutation. In conclusion, the Asserachrom® VWF:FVIIIB is easy to perform, standardized and accurate for type 2N VWD diagnosis with a 100% sensitivity and specificity.
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Affiliation(s)
- A Veyradier
- Service d'Hématologie Biologique, Hôpital Antoine Béclère, Clamart Cedex, France.
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9
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Varadi K, Rottensteiner H, Vejda S, Weber A, Muchitsch EM, Turecek PL, Ehrlich HJ, Scheiflinger F, Schwarz HP. Species-dependent variability of ADAMTS13-mediated proteolysis of human recombinant von Willebrand factor. J Thromb Haemost 2009; 7:1134-42. [PMID: 19422458 DOI: 10.1111/j.1538-7836.2009.03453.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND von Willebrand factor (VWF) is composed of a series of multimers, the sizes of which are regulated by the plasma metalloprotease ADAMTS13. OBJECTIVE Proteolysis of human recombinant VWF (rVWF) by ADAMTS13 present in the plasma of different species typically used as preclinical animal models was investigated to evaluate the efficacy and safety of rVWF. METHODS Degradation of rVWF was studied in vitro under moderate denaturing conditions and was monitored by multimer analysis, residual collagen binding, and immunoblot analysis. In vivo cleavage was determined by administration of rVWF to cynomolgus monkeys, rabbits and VWF-deficient mice and subsequent analysis of plasma samples by immunoblot. Plasma ADAMTS13 levels were determined with a synthetic human VWF peptide (FRETS-VWF73). RESULTS From the animals tested, only rabbit plasma was as efficient as human plasma in proteolysing rVWF in vitro. Mouse plasma virtually failed to cleave rVWF. Administration of human rVWF resulted in ADAMTS13-specific cleavage products in rabbits and, to a lesser extent, in cynomolgus monkeys at various doses of rVWF. Virtually no cleavage occurred in mice. ADAMTS13 activity levels in rabbit and monkey plasma were similar to those in human plasma and were not significantly altered upon infusion of rVWF up to very high doses, indicating that rVWF did not lead to an exhaustion of endogenous ADAMTS13 in both species. CONCLUSIONS The differences in susceptibility to cleavage of rVWF by different species need to be considered when interpreting the physiology of human rVWF from results of tests in animal models.
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Affiliation(s)
- K Varadi
- Baxter Innovations GmbH, Industriestrasse 67, Vienna, Austria
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Collins PW, Cumming AM, Goodeve AC, Lillicrap D. Type 1 von Willebrand disease: application of emerging data to clinical practice. Haemophilia 2008; 14:685-96. [PMID: 18510569 DOI: 10.1111/j.1365-2516.2008.01757.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
There has been much recent data published on type 1 von Willebrand disease (VWD) predominantly from three multi-centre cohort studies. These data have influenced a revision of the classification of type 1 VWD and have important implications for the management of this disorder. Patients with low von Willebrand factor (VWF) levels tend to have VWF mutations and VWD is transmitted predictably within families. In patients with VWF levels close to the lower end of the normal range, candidate mutations are found less often, ABO blood group is a more important factor and the disease has variable heritability within families. The importance of bleeding symptoms, in addition to VWF levels, in the diagnosis of type 1 VWD has been highlighted.
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Affiliation(s)
- P W Collins
- Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, University Hospital of Wales, Cardiff, UK.
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García K, Nabhani T, García J. The calcium channel alpha2/delta1 subunit is involved in extracellular signalling. J Physiol 2007; 586:727-38. [PMID: 18063658 DOI: 10.1113/jphysiol.2007.147959] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The alpha2/delta1 subunit forms part of the dihydropyridine receptor, an essential protein complex for excitation-contraction (EC) coupling in skeletal muscle. Because of the lack of a viable knock-out animal, little is known regarding the role of the alpha2/delta1 subunit in EC coupling or in other cell functions. Interestingly, the alpha2/delta1 appears before the alpha1 subunit in development and contains extracellular conserved domains known to be important in cell signalling and inter-protein interactions. These facts raise the possibility that the alpha2/delta1 subunit performs vital functions not associated with EC coupling. Here, we tested the hypothesis that the alpha2/delta1 subunit is important for interactions of muscle cells with their environment. Using confocal microscopy, we followed the immunolocalization of alpha2/delta1 and alpha1 subunits with age. We found that in 2-day-old myotubes, the alpha2/delta1 subunit concentrated towards the ends of the cells, while the alpha1 subunit clustered near the centre. As myotubes aged (6-12 days), the alpha2/delta1 became evenly distributed along the myotubes and co-localized with alpha1. When the expression of alpha2/delta1 was blocked with siRNA, migration, attachment and spreading of myoblasts were impaired while the L-type calcium current remained unaffected. The results suggest a previously unidentified role of the alpha2/delta1 subunit in skeletal muscle and support the involvement of this protein in extracellular signalling. This new role of the alpha2/delta1 subunit may be crucial for muscle development, muscle repair and at times in which myoblast attachment and migration are fundamental.
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Affiliation(s)
- Kelly García
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL 60612, USA
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12
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Tan FL, Ginsburg D. What a polyclonal antibody sees in von Willebrand factor. Thromb Res 2007; 121:519-26. [PMID: 17614124 PMCID: PMC2258224 DOI: 10.1016/j.thromres.2007.05.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 05/21/2007] [Accepted: 05/29/2007] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Von Willebrand factor (VWF) plays a critical role in hemostasis by carrying factor VIII (FVIII) and binding to specific ligands on the surface of blood platelets and within the blood vessel wall. MATERIALS AND METHODS We constructed a gene-specific phage display library containing small, random VWF fragments. Using this library, we mapped the repertoire of immune epitopes recognized by a commonly used commercial rabbit antihuman VWF polyclonal antibody. RESULTS A total of eight discrete epitopes within the VWF protein were identified, including two dominant epitopes that account for 74% of immuno selected VWF fragments. Comparison with previously mapped epitopes for mouse monoclonal antibodies reveals four overlapping regions that may identify common antigenic determinants. The distribution of these epitopes was not readily predicted from primary amino acid sequence divergence among these mammalian species or standard algorithms for the prediction of antigenicity, hydrophobicity, or surface probability. CONCLUSION Taken together with previous monoclonal antibody epitope mapping studies, our results suggest that a limited number of exposed domains on the surface of the human VWF protein may be the primary determinants of immunogenicity.
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Affiliation(s)
- Fen-Lai Tan
- Department of Internal Medicine and Department of Human Genetics, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
- Life Science Institute, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
| | - David Ginsburg
- Department of Internal Medicine and Department of Human Genetics, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
- Life Science Institute, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
- Howard Hughes Medical Institute, University of Michigan School of Medicine, Ann Arbor, MI 48109, USA
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13
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James PD, Paterson AD, Notley C, Cameron C, Hegadorn C, Tinlin S, Brown C, O'Brien L, Leggo J, Lillicrap D. Genetic linkage and association analysis in type 1 von Willebrand disease: results from the Canadian type 1 VWD study. J Thromb Haemost 2006; 4:783-92. [PMID: 16634747 DOI: 10.1111/j.1538-7836.2006.01860.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND von Willebrand disease (VWD) is the most common bleeding disorder known in humans, with type 1 VWD representing the majority of cases. Unlike the other variant forms of VWD, type 1 disease represents a complex genetic trait, influenced by both genetic and environmental factors. AIM To evaluate the contribution of the von Willebrand factor (VWF) and ABO blood group loci to the type 1 VWD phenotype, and to assess the potential for locus heterogeneity in this condition, we have performed genetic linkage and association studies on a large, unselected type 1 VWD population. METHOD We initially collected samples from 194 Canadian type 1 VWD families for analysis. After the exclusion of families found to have either type 2 or type 3 VWD, and pedigrees with samples from single generations, linkage and association analysis was performed on 155 type 1 VWD families. RESULTS AND CONCLUSION The linkage study has shown a low heterogeneity LOD score of 2.13 with the proportion of families linked to the VWF gene estimated to be 0.41. Linkage was not detected to the ABO locus in this type 1 VWD population. In the family-based association test, significant association was found between the type 1 VWD phenotype, the quantitative traits, VWF:Ag, VWF:RCo, and FVIII:C and the ABO 'O' and 'A' alleles and the VWF codon 1584 variant. There was also weak association with the -1185 promoter polymorphism and VWF:Ag, VWF:RCo, and FVIII:C plasma levels. These studies provide further evidence to support the role for genetic loci other than VWF and ABO in the pathogenesis of type 1 VWD.
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Affiliation(s)
- P D James
- Department of Medicine, Queen's University, Kingston, Canada
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14
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Millar CM, Brown SA. Oligosaccharide structures of von Willebrand factor and their potential role in von Willebrand disease. Blood Rev 2006; 20:83-92. [PMID: 16507387 DOI: 10.1016/j.blre.2005.02.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Oligosaccharides make up approximately 20% of the mass of VWF and although their structures are well established, their functional role remains unclear. Modification of the VWF oligosaccharide structures has been shown to result in increased plasma clearance of the protein. A mutation which alters cell type-specific expression of the Galgt2 glycosyltransferase gene in the RIIIS/J mouse results in an autosomal dominant partial quantitative deficiency of VWF. Increased plasma clearance of VWF has been demonstrated in some individuals with a partial quantitative deficiency of the protein and it is possible that variation in VWF glycosylation may contribute towards this. ABH antigens occur within the oligosaccharide component of VWF and may account for the variation in plasma VWF:Ag levels observed between individuals of different ABO blood groups. The structures and functional roles of the oligosaccharide side chains of VWF and possible pathogenetic mechanisms by which they may contribute towards VWD are reviewed in this article.
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Affiliation(s)
- Carolyn M Millar
- The Katharine Dormandy Haemophilia Centre and Haemostasis Unit, Royal Free and University College Medical School, Pond Street, London NW3 2QG, UK.
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15
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Schinstine M, Robert D. Pathologic quiz case: a 2-year-old boy with a hereditary bleeding disorder. Arch Pathol Lab Med 2003; 127:752-4. [PMID: 12741906 DOI: 10.5858/2003-127-752-pqcayo] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Malcolm Schinstine
- Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756-0001, USA.
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Sugimoto M, Matsui H, Mizuno T, Tsuji S, Miyata S, Matsumoto M, Matsuda M, Fujimura Y, Yoshioka A. Mural thrombus generation in type 2A and 2B von Willebrand disease under flow conditions. Blood 2003; 101:915-20. [PMID: 12393671 DOI: 10.1182/blood-2002-03-0944] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
To explore the mechanisms that underlie the bleeding tendency in type 2A and 2B von Willebrand disease (VWD), we analyzed the mural thrombus generation process on a collagen surface under physiologic blood flow in a perfusion chamber using whole blood from these VWD patients. At a low shear rate (50 s(-1)), thrombus generation in all type 2A and 2B VWD patients was comparable to that of healthy controls. At a high shear rate (1500 s(-1)), thrombus generation was impaired in all type 2A patients, whereas that in type 2B VWD patients varied from normal to significantly defective, as judged by epifluorescence microscopy of thrombus surface coverage. However, in type 2B patients who showed normal thrombus generation at 1500 s(-1), the height and volume of thrombi was significantly reduced, albeit with the normal surface coverage, compared with control thrombi, and von Willebrand factor (VWF) was poorly distributed within the type 2B thrombus mass when analyzed in detail by confocal laser scanning microscopy. Addition of purified VWF to patient blood completely reversed the defective spatial thrombus growth in type 2B VWD. Thus, our results confirm the impaired thrombus generation in type 2B VWD, which has never been demonstrable in previous in vitro soluble-phase platelet aggregation assays, and point to the critical function of larger VWF multimers in the proper spatial growth of mural thrombi under high shear rate conditions.
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