bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Factor VIII Minigene Comprising the Truncated Intron I of Factor IX Highly Improves the In Vitro Production of Factor VIII
Authors: Plantier Jean-Luc , Rodriguez Marie-Hélène , Enjolras Nathalie , Attali Olivier , Négrier Claude 
Published: March 2018

SummaryThe biosynthesis of coagulation factor VIII (FVIII) is hampered by successive controls that limit its production. To improve this production, a truncated intron I sequence of factor IX (TFIXI1) was inserted in FVIII cDNA in place of FVIII introns 1, 12 and 13 and also as a combination between introns 1 and 12, and introns 1 and 13. The intron 12 and 13 locations were targeted because this region was previously shown to contain a transcriptional silencer. The expression of FVIII in CHO and HepG2 cells revealed important variations in the properties of the minigenes depending on the TFIXI1 insertion sites. In FVIII intron 13 location the TFIXI1 seemed to diminish the transcriptional silencer activity, whereas it was poorly spliced in intron 12 position. Among the five constructs, FVIII I1+13 leaded to a significant improvement in FVIII secretion (13 times) that was associated with a dramatic intracellular accumulation in cells. Therefore, the FVIII I1+13 minigene could represent a particular interest to produce recombinant FVIII in vitro as well as in the aim of gene therapy of haemophilia A.
Selection of Phages that Inhibit vWF Interaction with Collagen under both Static and Flow Conditions
Authors: Ulrichts H. , Depraetere H. , Harsfalvi J. , Deckmyn H. 
Published: March 2018

SummaryPhages from a pentadecamer phage display library were selected for binding to vWF by affinity panning. Bound phages were selectively eluted with human collagen type I. After the third round of panning 95% of individual phage clones bound to vWF. The B8-phage inhibited the binding of collagen to vWF with an IC50 of 0.6 × 1010 phages/ml, and of vWF to collagen with an IC50 of 1.0 × 1010 phages/ml at 0.5 μg/ml vWF. Under flow conditions, 1.5 × 1011 B8-phage/ml nearly completely inhibited platelet deposition on a human collagen type I coated surface at a shear rate of 1200 s-1, while phages without an insert had no effect. The peptide corresponding to the one displayed on the B8-phage competed with the phage for binding to vWF with an IC50 of 30 μg/ml (16 μM). The peptide furthermore inhibited vWF-binding to collagen with a maximum of 40% at a concentration of 1.25 mg/ml (650 μM), higher concentrations of peptide could not improve this. We thus have selected phages that are potent vWF-binders and that can be used as tools to detect vWF, to inhibit vWF-collagen interaction and to further analyse the role of vWF-collagen binding.
Plasma PAI-1 Levels in Obese Children – Effect of Weight Loss and Influence of PAI-1 Promoter 4G/5G Genotype
Authors: Dalmau Jaime , Falcó Cristina , Berbel Octavio , Castelló Remedios , España Francisco , Aznar Justo , Estellés Amparo 
Published: March 2018

SummaryAn association between an increase in plasminogen activator inhibitor type 1 (PAI-1) and obesity, and also between elevated levels of PAI-1 and the presence of PAI-1 promoter 4G allele has been described in adults and can contribute to increased risk of cardiovascular disease. It has also been suggested that in adults a decrease in adiposity has beneficial effects on the haemostatic system. However, less information is available regarding adiposity and fibrinolysis in children. The aim of the present study is to evaluate the effect of weight loss and the influence of the PAI-1 promoter 4G/5G genotype on the fibrinolytic system and lipid parameters in obese children. The clinical groups included 102 obese children and 105 controls of similar age and sex distribution. A significant decrease in fibrinolytic activity due to a significant increase in PAI-1 antigen and activity levels was observed in the obese children in comparison with the control group. In obese children, no significant differences in PAI-1 levels between the PAI-1 4G/5G genotypes were obtained. A significant correlation was observed between PAI-1 antigenic and functional levels and body mass index (BMI), as well as between PAI-1 levels and both triglyceride and insulin levels. No correlation between PAI-1 levels and either cholesterol or glucose levels was observed.After a three-month period of treatment to reduce weight, an increase in fibrinolytic activity due to a decrease in PAI-1 levels was observed in the obese children who had reduced their BMI in comparison with the group of obese children who did not show a decrease in their BMI. No significant differences between the two groups with respect to the variations in tissue type plasminogen activator and fibrinogen levels were obtained after three months of intervention to reduce weight. A significant correlation was observed between variations in BMI and variations in PAI-1 levels, and a significant inverse correlation was also observed between previous PAI-1 levels and variation in PAI-1 levels. Therefore, the largest decrease in PAI-1 levels was observed in the obese children with the highest previous PAI-1 levels.In conclusion, a decrease in BMI in obese children shows a favourable effect on the fibrinolytic system due to a decrease in PAI-1 levels. However, no influence of 4G/5G genotype on PAI-1 levels was observed.
Human Endothelial Cell-derived Nuclear Proteins that Recognise Polymorphic DNA Elements in the von Willebrand Factor Gene Promoter Include YY1
Authors: Costa Magdaline , Grant Peter , Rice Gillian , Futers Simon , Medcalf Robert 
Published: March 2018

SummaryFour common base-change polymorphisms have been found in the von Willebrand factor gene promoter: (-1793 C/G, -1234 T/C, -1185 G/A and -1051 A/G). All four polymorphisms are in strong linkage dis-equilibrium and recent reports have indicated these polymorphisms are associated with plasma vWF:Ag levels suggesting that one or more of these elements influence regulation of the vWF gene. We report that human endothelial cell-derived trans-acting factors display allelic preferences in binding activity to each polymorphic site. The common A allele variant of the –1051 polymorphism and the rarer A allele variant of the –1185 polymorphism provided specific binding of nuclear proteins. The G allele counterpart of these two variants did not produce any complex formation indicating that the nucleotide substitution at these positions alters the DNA binding ability of nuclear factors. The two alleles of the –1234 polymorphism produced two complexes with a similar migration pattern however stronger binding was found to the common T variant of this allele. Two specific complexes associated with the rarer G allele of the –1793 polymorphism, but only one associated with the C allele. Supershift experiments revealed that the trans-acting factor YY1 recognised the slower migrating complex formed on the –1234 T/C and the –1051 A polymorphic sites with a strong binding preference for the –1234 T allele variant. The identification of YY1 as a component of the factors that recognise these elements suggests that this ubiquitous nuclear protein may play a role in the regulation of the vWF promoter.
A Monoclonal Antibody to Platelet Type III Collagen-binding Protein (TIIICBP) Binds to Blood and Vascular Cells, and Inhibits Platelet Vessel-wall Interactions
Authors: Monnet Emmanuel , Depraetere Hilde , Legrand Chantal , Deckmyn Hans , Fauvel-Lafève Françoise 
Published: March 2018

SummaryTIIICBP is a new platelet receptor involved in platelet-type III collagen and platelet-subendothelium interactions. This receptor is composed of a doublet of 72-68 kDa proteins. In this study, the major protein (68 kDa) was purified and used to produce monoclonal antibodies. One of these antibodies, 7F4, binds to platelets as confirmed by flow cytometry. 7F4 inhibited platelet contact, spreading and aggregation induced by type III collagen. Under flow conditions, 7F4 prevented platelet interactions with type III collagen, endothelial cell matrix and the KOGEOGPK type III collagen octapeptide: the specific sequence recognized by TIIICBP. On the other hand, 7F4 had no effect on platelet-type I collagen interactions. TIIICBP was also detected on lymphocytes, granulocytes and monocytes. TIIICBP was expressed on endothelial cells and fibroblasts but not on smooth-muscle cells. These results show that TIIICBP is expressed on several cell types and participates in cell adhesion to the subendothelium.
αIIbβ3 and Its Antagonism at the New Millennium
Authors: Cierniewski Czeslaw , Xiao Zihui , Haas Thomas , Byzova Tatiana , Plow Edward 
Published: March 2018

SummaryBecause of its major role in regulating platelet functions and its prominence on the cell surface, integrin αIIbβ3 has been the subject of intensive investigations. Such studies have provided substantial insights into its structure-function relationships and have led to the development of anti-thrombotic drugs that target the receptor. Nevertheless, recent findings have indicated that our understanding of the structure and function of αIIbβ3 remains inadequate. This article addresses two aspects of still evolving αIIbβ3 function: 1) the interface between αIIbβ3 and the blood coagulation system, resulting from interaction of prothrombin with the receptor; and 2) the molecular basis for recognition of the RGD and the fibrinogen γ-chain peptide ligands by αIIbβ3. As illustrated by these two examples, there is still much to be learned about αIIbβ3 if we are to fully appreciate its functions and its potential as a therapeutic target.
Physiopathology and Regulation of Factor XIII
Authors: Ichinose Akitada 
Published: March 2018

SummaryFactor XIII is a plasma transglutaminase. Transglutaminases are at least 8 enzymes which cross-link a number of proteins. This type of reaction not only enhances the original functions of substrate proteins, but also adds new functions to them. Factor XIII in plasma is a tetramer (A2B2), and the A subunit contains the active site. Although transglutaminases are homologous, the nucleotide sequences in their 5’-flanking region differ significantly. Accordingly, transcription factors play a major role in the cell type-specific expression of each transglutaminase. A variety of missense and nonsense mutations, and deletions/insertions with or without out-of-frame shift/premature termination and splicing abnormalities have been identified in the genes for A and B subunits in factor XIII deficiency. In some cases, the mRNA level of the A or B subunit was severely reduced. Molecular and cellular bases have also been explored by expression experiments and by molecular modeling. In most cases, impaired folding and/or conformational change of the mutant A or B subunit leads to both intra- and extra-cellular instability, which is responsible for factor XIII deficiency.
Oral Contraceptives, Hormone Replacement Therapy and Thrombosis
Authors: Helmerhorst F. M. , Vandenbroucke J. P. , Rosendaal F. R. 
Published: March 2018

SummaryOral contraceptives and hormone replacement therapy are used by hundreds of millions of women worldwide. Since the early 1960s it is known that female hormones increase the risk of venous thrombosis, myocardial infarction and stroke. This risk is still present with current low-dose oral contraceptives and, even though in absolute terms the risk is small, oral contraceptives form the major cause of thrombotic disease in young women. The risk is higher during the first year of use (up to 1 per 1000 per year), with the use of desogestrel- or gestodene-containing oral contraceptives (“third generation progestogens”) and among women with a prothrombotic predispositon. Hormone replacement therapy increases the risk of venous thrombosis, while results of randomised trials so far do not substantiate the expectation of a beneficial effect on the risk of arterial cardiovascular disease. First results are emerging that specific subgroups of women, with prothrombotic or other abnormalities, may be at risk, especially during the first years of use of hormone substitution.
Getting at the Variable Expressivity of Von Willebrand Disease
Authors: Levy Gallia , Ginsburg David 
Published: March 2018

SummaryVon Willebrand disease (VWD) is a heterogeneous bleeding disorder caused by abnormalities of von Willebrand factor (VWF). VWF levels vary widely in the general population, and this variation is likely to be a major factor accounting for the incomplete penetrance and variable expressivity of VWD. In addition, variation in VWF level may play an important role in determining the risk of venous thrombosis. A large component of the variation in VWF level in the general population has been shown to be attributable to genetic factors. This review will focus on the current understanding of the genetic causes for variation in VWF level, and will highlight future directions for getting at the variable expressivity of von Willebrand disease.
The Molecular Basis of Inherited Afibrinogenaemia
Authors: Neerman-Arbez Marguerite 
Published: March 2018

SummaryThis article reviews the substantial progress made in understanding the molecular basis of inherited afibrinogenaemia (or congenital afibrinogenaemia), an autosomal recessive disorder characterised by the complete absence of detectable fibrinogen. The identification in 1999 of the first genetic defect, recurrent homozygous deletions of approximately 11 kb of the fibrinogen alpha-chain (FGA) gene, revealed that the disease was caused by defective fibrinogen synthesis, and led to the subsequent analysis of the three fibrinogen genes in other affected individuals with the identification of numerous causative mutations. Combined analyses of more than thirty unrelated afibrinogenaemia families from various ethnic groups have shown that the majority of patients have truncating mutations in the FGA gene although intuitively all three fibrinogen genes might be equally implicated. These results will facilitate molecular diagnosis of the disorder, permit prenatal diagnosis for families who so desire, and pave the way for new therapeutic approaches such as gene therapy.
The Vascular Biology of the Glycoprotein Ib-IX-V Complex
Authors: Shen Yang , Dopheide Sacha , Gardiner Elizabeth , Andrews Robert , Berndt Michael 
Published: March 2018

SummaryIt has long been recognized that binding of von Willebrand factor (vWf) by the platelet membrane glycoprotein (GP) Ib-IX-V complex initiates the cascade of events leading to thrombosis and haemostasis. In the last several years, however, it has become apparent that the GP Ib-IX-V complex plays a much broader role in vascular biology, a recognition in part due to the identification of novel adhesive ligands for GP Ib-IX-V such as P-selectin and Mac-1. Binding of vWf by the GP Ib-IX-V complex is also important in formation of the developing thrombus. Platelets can utilize the GP Ib-IX-V complex and PSGL-1 to roll on activated endothelium via surface-expressed endothelial P-selectin. The GP Ib-IX-V complex can bind the I domain of Mac-1, a binding interaction potentially relevant to transmigration of macrophages through mural thrombus, a process required for vessel remodeling post angioplasty. This review will focus on recent advances in our understanding of the structure and function of this important platelet receptor, with particular emphasis on insights made within the last two years.
Cytoskeletal Proteins and Platelet Signaling
Authors: Fox Joan 
Published: March 2018

SummaryThe actin filament network fills the cytoplasm of unstimulated platelets and connects with a submembranous latticework of short cross-linked actin filaments, known as the membrane skeleton. One function of the cytoskeleton is to direct the contours of the membrane in the unstimulated platelet and the rapid changes in shape in the activated platelet. Activation-induced changes result from events such as phosphorylation or calpain-induced cleavage of cytoskeletal proteins. The specific reorganizations depend upon the combination of signals to which platelets are exposed. A second function of the cytoskeleton is to bind other cellular components; it binds signaling molecules, localizing them to specific cellular locations; it binds the plasma membrane regulating properties of the membrane, maintaining microdomains in the membrane, or regulating activities of membrane proteins. In this way, the cytoskeleton plays a critical role in regulation of spatial organizations and, thus, in the integration of cellular activities.
β3 Tyrosine Phosphorylation in αIIbβ3 (Platelet Membrane GP IIb-IIIa) Outside-in Integrin Signaling
Authors: Nannizzi-Alaimo Lisa , Prasad K. S. Srinivasa , Phillips David 
Published: March 2018

SummaryThe platelet integrin αIIbβ3 not only binds fibrinogen and von Willebrand factor to mediate platelet aggregation and adhesion, it also serves as a signaling receptor. Platelet agonists such as ADP, thrombin and collagen induce “inside-out” signaling which activates the receptor function of αIIbβ3 for soluble fibrinogen. Subsequent platelet aggregation leads to “outside-in” signaling, inducing platelet aggregate stabilization and triggering a variety of functions important to platelet physiology. This review focuses on the role of β3 tyrosine phosphorylation in αIIbβ3 outside-in signaling. Tyrosine phosphorylation of β3 in platelets is a dynamic process which is initiated upon platelet aggregation and also by adhesion of platelets to immobilized fibrinogen. Tyrosine phosphorylation occurs on the β3 integrin cytoplasmic tyrosine (ICY) domain, a conserved motif found in thesubunits of several integrins. β3 ICY domain tyrosine phosphorylation induces the recruitment of two proteins to the cytoplasmic domains of αIIbβ3: the cytoskeletal protein myosin, important to clot retraction; and the signaling adapter protein Shc, important to platelet stimulation. The critical role of β3 tyrosine phosphorylation to platelet function was established by the diYF mouse, a novel strain which expresses an αIIbβ3 in which the two β3 ICY domain tyrosines have been mutated to phenylalanine. These mice are selectively impaired in outside-in αIIbβ3 signaling, with defective aggregation and clot-retraction responses in vitro, and an in vivo bleeding defect which is characterized by a pronounced tendency to rebleed. Taken together, the data suggest that the β3 tyrosine phosphorylation signaling mechanism is important to αIIbβ3 function and might be applicable to a wide variety of integrin-mediated events.
Interendothelial Junctions and their Role in the Control of Angiogenesis, Vascular Permeability and Leukocyte Transmigration
Authors: Spagnuolo Raffaella , Bazzoni Gianfranco , Dejana Elisabetta 
Published: March 2018

SummaryEndothelial cell-cell junctions play an important role in vascular hemostasis. The two junctional proteins VE-cadherin and JAM-1 are localized at adherens and tight junctions, respectively. VE-cadherin is only expressed by endothelial cells, suggesting that it can exert cell specific function. Absence of VE-cadherin or blocking of its adhesive activity prevents a normal organization of new vascular structures, suggesting that VE-cadherin may be a molecular target of antiangiogenic therapy. In addition, the ability of permeability-increasing agents and adherent leukocytes to modify VE-cadherin/catenin organization may be related to a role in the control of vascular permeability and leukocyte infiltration. JAM-1 is an integral membrane protein expressed in endothelial and epithelial cells. Its extracellular domain can dimerize and bind homophilically. The intracellular domain (and in particular a PDZ-binding motif) enables JAM-1 to interact with structural and signaling proteins. Study of the molecular interactions of JAM-1 may help explain mechanisms of JAM-mediated function, such as control of paracellular permeability and leukocyte transmigration.
Anti-GPIIb/IIIa Drugs: Current Strategies and Future Directions
Authors: Coller Barry 
Published: March 2018

SummaryThree platelet glycoprotein (GP) IIb/IIIa receptor antagonists have been approved as adjunctive therapy to decrease the ischemic complications of percutaneous coronary interventions (PCI) and/or unstable angina. They include the chimeric murine/human monoclonal antibody 7E3 Fab fragment (abciximab), a cyclic heptapeptide based on the KGD amino acid sequence (eptifibatide), and a nonpeptide mimetic of the RGD sequence (tirofiban). The agents are very effective in providing both short-term and long-term benefit after PCI, and one agent has also demonstrated a progressive long-term mortality benefit. The long-term mortality benefit is highly cost-effective when compared to other medical interventions. The benefits in treating unstable angina without PCI are less dramatic and robust, with some agents providing no benefit. Severe thrombocytopenia is an infrequent, but potentially serious, complication of therapy with all of the agents. The risk of major bleeding is increased only minimally or not at all by the drugs. Currently, a number of new indications for GPIIb/IIIa antagonists are under study, including acute myocardial infarction (± thrombolytic therapy, ± PCI) and stroke. In addition to their impact on improving outcome, the results of clinical trials with these agents provide crucial insights into the contribution of GPIIb/IIIa-mediated platelet function in the pathophysiology of thrombotic vascular disease.
Immundefekte als Ursache von chronisch-entzündlichen Erkrankungen des Darmes
Authors: Gerner P. , Speckmann C. , Klemann C. , Tegtmeyer D. , Baumann U. 
Published: March 2018

ZusammenfassungChronisch-entzündliche Darmerkrankungen (CED), mit ihren beiden prominentesten Vertretern M. Crohn und Colitis ulcerosa, zeichnen sich durch eine multifaktorielle Ätiologie mit komplexer Regulation zwischen polygenetischer Grundlage und Umwelteinflüssen aus. In den letzten Jahren wurden zahlreiche, jedoch insgesamt seltene, monogenetische Erkrankungen identifiziert, die sich mit einem CED-Phänotyp manifestieren können. Das frühe Erkennen und Anpassen der Therapien dieser heterogenen, immunologischen Erkrankungen sind von hoher Relevanz für den weiteren Verlauf der Erkrankung. In diesem Review diskutieren wir charakteristische Befunde und Umstände, die an das Vorliegen einer monogenetischen Ursache für die intestinale Inflammation denken lassen: Hinweisend können ein früher Krankheitsbeginn, ein Versagen klassischer Therapien, elterliche Konsanguinität, eine auffallende Infektanfälligkeit oder CED-untypische Begleiterkrankungen, Pathologien oder Blutwerte sein. Wir beschreiben ausgewählte Erkrankungen anhand von Fallbeispielen und zeigen auf, wie diese Erkrankungen durch die Kombination von anamnestischen Angaben und klinischen, zellulären sowie genetischen Untersuchungen diagnostiziert werden können. Hierfür schlagen wir eine gestufte, diagnostische Strategie vor, um diesen außergewöhnlichen Erkrankungen als Differenzialdiagnose einer CED nachzugehen.