bluuebunny/crossref_metadata_2025_split huggingface dataset:
15 Deoxy Δ12,14 PGJ2 Induces Procoagulant Activity in Cultured Human Endothelial Cells
Authors: Xie Shaoping , O’Regan David , Kakkar Vijay , Scully Michael 
Published: March 2018

Summary15 deoxy Δ12,14 PGJ2 (15d-PGJ2), a high affinity ligand of peroxisome proliferator-activated receptor γ (PPAR γ has been proposed to act as a negative feedback regulator of the inflammatory response. We investigated the effect of 15d-PGJ2 on the anticoagulant property of endothelial cells. 15d-PGJ2 stimulated a moderate but sustained increase in tissue factor (TF) activity in HUVECs and EA.hy926 cells while causing a partial loss of thrombomodulin (TM) activity. When cells were co-treated with 15d-PGJ2 and TNF-α, the subsequent elevation of TF activity was synergistically increased over that of cells treated with TNF-α, alone and the decline of TF activity after 24 h was less marked than TNF-α, alone. The induction of TF by 15d-PGJ2 alone and in combination with TNF-α, was reduced in the presence of PD 98059, suggesting the participation of the MEK/ERK pathway. The thiazolidinedione PPAR γ agonist ciglitazone had no effect on TF levels but reduced the expression of endothelial protein C receptor. The ability of 15d-PGJ2 to enhance a procoagulant phenotype arising from TNF-α, suggests a pro-inflammatory role for the prostaglandin.
Adipocyte Hypertrophy in Stromelysin-3 Deficient Mice with Nutritionally Induced Obesity
Authors: Van Hoef B. , Frederix L. , Rio M.-C. , Collen D. , Lijnen H. R. 
Published: March 2018

SummarySeveral matrix metalloproteinases (MMPs), including the stromelysins MMP-3 and MMP-11, are expressed in adipose tissue. To investigate a potential role of MMP-11 (stromelysin-3) in adipose tissue development, five-week-old male wild-type mice (MMP-11+/+) or mice with deficiency of MMP-11 (MMP-11−/−) were fed a high fat diet (HFD, 42% fat) for 15 weeks. Haematologic parameters, including white and red blood cells, platelets, haemoglobin and haematocrit, and metabolic parameters including glucose, triglycerides and total cholesterol were not different for both genotypes. At the time of sacrifice, the body weight of the MMP-11-/mice was higher than that of the MMP-11+/+ mice (36 ± 1.4 g versus 29 ± 0.9 g, p = 0.0002). The weight of the isolated subcutaneous (SC) and gonadal (GON) fat deposits was also higher in MMP-11−/−mice (620 ± 150 mg versus 280 ± 28 mg for SC fat, and 970 ± 180 mg versus 430 ± 62 mg, p < 0.05, for GON fat). Adipocytes in MMP-11−/−adipose tissue were hypertrophic as compared to MMP-11+/+ adipocytes (volume of 57 ± 12 × 103 µm3 versus 31 ± 2.4 × 103 µm3 for SC fat, and 100 ± 18 × 103 µm3 versus 57 ± 7.6 × 103 µm3 for GON fat; both p < 0.06). In nutritionally induced obesity models in mice a potential role of the fibrinolytic system was suggested in adipocyte hypertrophy. The hypertrophy observed in this model is, however, not related to changes in fibrinolytic parameters, as suggested by our finding that levels of t-PA, u-PA and PAI-1 antigen as well as t-PA and u-PA activity were not different in SC or GON adipose tissue extracts of both genotypes. As the main biological function of MMP-11 remains unknown, it is not clear whether the adipocyte hypertrophy in MMP-11−/−adipose tissue is directly related to the deficiency or to other pathways affected by MMP-11.
No Association of Plasma Prothrombin Concentration or the G20210A Mutation with Incident Cardiovascular Disease
Authors: Smiles Adam , Jenny Nancy , Tang Zhonghua , Arnold Alice , Cushman Mary , Tracy Russell 
Published: March 2018

SummaryProthrombin is a key factor in blood clotting, a process intimately involved in thrombotic disease. We assessed prothrombin levels and G20210A genotype in a case-control study within the Cardiovascular Health Study. Cases included angina, myocardial infarction, stroke, and the presence of MRI-detectable infarcts (n ≈ 250 each). Populationbased controls free of clinical cardiovascular disease (CVD) (n ≈ 500) and a subset free of clinical and subclinical CVD (n ≈ 250) were used for comparison. The 20210 A allele, frequency 2.9%, was associated with higher mean prothrombin levels: 166.3 vs. 139.5 µg/ml (P <0.001). Significant correlates of prothrombin included gender, plasma lipids, other vitamin K-dependent proteins, and inflammatory markers, but not race, smoking, hypertension, diabetes, measures of subclinical CVD, or markers of procoagulant activity. Compared to controls, neither genotype nor prothrombin level was associated with any CVD case group. We conclude that, in the elderly, neither prothrombin level nor 20210 genotype were associated with either CVD risk factors or events. This is consistent with the lack of association of prothrombin levels with measures of underlying CVD or procoagulant markers.
Antibodies to Heterologous Proteins in Hemophilia A Patients Receiving Recombinant Factor VIII (Recombinate™)
Authors: Ingerslev Jørgen , Christiansen Kirsten , Ravn Hanne , Gomperts Edward , Bray Gordon ,   The Recombinate Study Group
Published: March 2018

SummaryAs a consequence of the manufacturing process, trace quantities of Chinese hamster ovary cell protein, bovine serum albumin and murine immunoglobulin G are present in Recombinate™ recombinant human factor VIII (rhFVIII). The development of antibodies (Abs) to these heterologous proteins was evaluated during long-term rhFVIII therapy of hemophilia A in 68 previously treated and 73 previously untreated patients. Ab prevalence was also assessed in 157 non-hemophilic subjects. Abs against heterologous proteins could be detected in varying percentages of patients and non-hemophilic subjects. Abs arose in patients sporadically, and levels were typically low. There were no adverse events associated with development or presence of anti-heterologous protein Abs. These data indicate that sustained immune responses to trace levels of heterologous proteins are very infrequent during long-term rhFVIII therapy.
Nonsense Mutation in Exon-19 of GPIIb Associated with Thrombasthenic Phenotype. Failure of GPIIb(Δ597-1008) to Form Stable Complexes with GPIIIa
Authors: Arias-Salgado Elena , Tao Jianming , González-Manchón Consuelo , Butta Nora , Vicente Vicente , Ayuso Matilde , Parrilla Roberto 
Published: March 2018

SummaryWe report the molecular genetic analysis of a patient with thrombasthenic phenotype. The lack of surface platelet GPIIb-IIIa complexes and the presence of GPIIIa suggested it was a case of type I Glanzmann’s thrombasthenia due to a mutation in GPIIb. Single stranded conformational polymorphism analysis (SSCP) of exon-19 of GPIIb showed polymorphic DNA bands. The DNA sequence of exon-19 revealed the presence of a homozygous C1882T transition that changes residue R597 to STOP codon. Since no other mutations were found in either GPIIb or GPIIIa it is concluded that the C1882T substitution in GPIIb is responsible for the thrombasthenic phenotype of the patient. The lack of platelet GPIIb-mRNA in the proband indicates instability of the [C1882T]GPIIb-mRNA. Coexpression of normal GPIIIa and GPIIb(Δ597-1008) in CHO cells failed to show surface expression of GPIIb(Δ597-1008)-IIIa complexes. Immunoprecipitation analysis demonstrated that GPIIb(Δ597-1008) may indeed complex GPIIIa; however, the association is either unstable or incapable of progressing along the secretory pathway.
Release from Intracellular Stores Is Responsible for Calcium Signaling with von Willebrand Factor in Human Platelets
Authors: Milner Elizabeth , Zheng Qi , Kermode John 
Published: March 2018

SummaryInteraction of von Willebrand factor (VWF) with the platelet promotes hemostasis upon vascular injury. Such interaction raises intracellular free calcium concentration ([Ca2+]i) and induces platelet activation. The platelet [Ca2+]i increase is generally attributed to influx across the plasma membrane. The present study defined the contribution of intracellular calcium stores. Platelet [Ca2+]i was monitored with Fura-PE3. Ristocetin-mediated binding of VWF transiently elevated [Ca2+]i after a lag phase. Studies with 63 healthy donors consistently revealed a VWF-induced platelet [Ca2+]i signal in the absence of extracellular calcium; there was only modest enhancement with extracellular calcium. Blockade of plasma membrane calcium channels did not diminish the signal, whereas depletion or blockade of the intracellular calcium stores abolished it. These findings imply that release from intracellular stores is responsible for the VWF-induced platelet [Ca2+]i increase. Influx across the plasma membrane plays no more than a minor role, probably representing “capacitative entry” to refill the intracellular stores.
Identification of Critical Residues for Ligand Binding in the Integrin β3 I-domain by Site-directed Mutagenesis
Authors: Yamanouchi Jun , Tamura Tatsushiro , Fujita Shigeru , Hato Takaaki 
Published: March 2018

SummaryTo define the structural basis of ligand recognition by αIIb β3, we conducted site-directed mutagenesis of residues located on the top surface of the β3 I-domain that is homologous to the I-domain of several α subunits and contains a putative ligand binding site. Here we identify D158 and N215 in β3 as novel residues critical for ligand binding. Alanine substitution of D158 or N215 abolished binding of a ligand-mimetic antibody and fibrinogen to αIIb β3 induced by different types of integrin activation. CHO cells expressing recombinant αIIb β3 bearing D158A or N215A mutation did not adhere to fibrinogen. These mutations had the same effect on ligand binding to another β3 integrin, αV β3. Compared to the αI-domain structure, the βB-βC loop containing D158 in the β3 I-domain is quite different in length and sequence. These results suggest that the structure for ligand recognition is different in the βI- and αI-domains.
Prothrombin G20210A is a Bifunctional Gene Polymorphism
Authors: Carter Angela , Sachchithananthan Mythily , Stasinopoulos Stan , Maurer Fabienne , Medcalf Robert 
Published: March 2018

SummaryThe G20210A polymorphism has been shown to alter the efficiency of prothrombin mRNA processing. Here we show that the G20210A mutation also alters prothrombin mRNA stability. Three-fold more prothrombin protein and mRNA were produced in NIH-3T3 cells transfected with the prothrombin cDNAs containing the 20210A variant compared to cells expressing the 20210G variant. mRNA stability assays using chimeric globin transcripts harboring the G or A variant of the 97 nt prothrombin 3’-UTR indicated that the 20210G variant conferred greater instability to the globin reporter transcript than the A variant in transfected HepG2 cells. Both variants of the prothrombin 3’-UTR were shown to provide binding sites for a number of cellular proteins including HuR, an RNA binding protein associated with mRNA stability. Our results indicate that the G20210A is a bifunctional polymorphism, as it not only alters the efficiency of mRNA processing, but also the decay rate of prothrombin mRNA.
The Parasitic Hematophagous Worm Haemonchus contortus Inhibits Human Platelet Aggregation and Adhesion: Partial Purification of a Platelet Inhibitor
Authors: Crab Annick , Noppe Wim , Pelicaen Conny , Van Hoorelbeke Karen , Deckmyn Hans 
Published: March 2018

SummaryBlood sucking parasites elaborate mechanisms to counteract the hemostatic system of their victim. Haemonchus contortus worms use several mechanisms directed against the normal platelet hemostatic function. Platelet adhesion onto collagen and fibrinogen, and the ristocetin-mediated interaction of von Willebrand Factor with glycoprotein (GP) Ib were inhibited by the protein extract of adult worms. Also platelet aggregation induced by collagen, thrombin, ADP, ristocetin or A23187 was inhibited. Although we obtained evidence for interference with fibrinogen binding to GPIIb/IIIa, the strongest inhibition was seen when the agonists collagen or thrombin were used. A small multisubunit inhibitor of collagen-induced platelet aggregation was partially purified using anion exchange chromatography, gelfiltration and RP-HPLC. The inhibitor has a pI between 4 and 6.5, elutes with a molecular weight of 23,800 Da after gelfiltration, and is part of the elaborate broad-spectrum antiplatelet activity that results in the potent synergistic anti-hemostatic cocktail produced by H. contortus.
Tissue Factor Pathway Inhibitor Reduces Experimental Lung Metastasis of B16 Melanoma
Authors: Meyer Todd , Chang Jen-Yea , Amaya Mildred , Siddiqui Farooq , Desai Hina , Francis John , Amirkhosravi Ali 
Published: March 2018

SummaryThe importance of tissue factor (TF) in tumor biology has been highlighted by studies suggesting its involvement in cell signaling, metastasis and angiogenesis. Since many animal studies have shown that anticoagulant therapy can reduce experimental metastasis, we studied whether the natural inhibitor of TF-mediated blood coagulation, Tissue Factor Pathway Inhibitor (TFPI), might be similarly effective. Using a murine experimental model, we found that intravenous injection of recombinant murine TFPI immediately before introduction of tumor cells reduced metastasis by 83% (P <0.001). B16 murine melanoma cells stably transfected with a TFPI expression vector exhibited reduced lung seeding following intravenous injection by 81% (P <0.001) compared with controls. No difference in primary tumor growth was observed between TFPI+ and control cells. Mice receiving intravenous somatic gene transfer of sense TFPI expression vector developed 78% fewer lung nodules than controls (P <0.05). We conclude that TFPI has significant anti-metastatic activity in this experimental model.
Randomised, Double Blind, Multicentre, Placebo Controlled Study of Sulodexide in the Treatment of Venous Leg Ulcers
Authors: Scondotto Gaetano , Agnelli Giancarlo , Aloisi Daniele , Palazzini Ernesto , Zamboni Villiam , Coccheri Sergio ,   for the venous arm of the SUAVIS (Sulodexide Arterial Venous Italian Study) Group
Published: March 2018

SummarySulodexide, a highly purified glycosaminoglycan, was investigated for treatment of venous leg ulcers. Patients (n = 235) undergoing local treatment including wound care and compression bandaging, were randomised to receive either sulodexide or matching placebo for three months. Primary study endpoint was complete ulcer healing after 2 months; secondary endpoints were ulcer healing at 3 months and the time-course changes of ulcer areas.The proportion of patients with complete ulcer healing was higher with sulodexide at 2 months (p = 0.018) and 3 months. The “number needed to treat” to obtain one additional patient healed with sulodexide was 7 at 2 months and 5 at 3 months. The changes in ulcer surface area with time were significant for sulodexide only (p = 0.004). Fibrinogen significantly decreased in sulodexide patients (p = 0.006).In conclusion, sulodexide associated with local treatment proved to be effective and well tolerated in the management of venous leg ulcers.
Tissue Factor Expression on Monocyte Subpopulations during Normal Pregnancy
Authors: Wallace Julie , Gilmore W. S. , McFaul P. , Alexander H. D. , Holmes Valerie 
Published: March 2018

SummaryPregnancy is often referred to as a hypercoagulable state due to changes in the haemostatic system. Tissue factor (TF) is the initiator of blood clotting in vivo. The effect of pregnancy on monocyte TF expression was determined in a longitudinal case control study (89 pregnant, 39 non-pregnant). Using whole blood flow cytometry and CD14 as a monocyte marker, TF expression was measured on all CD14 positive, CD14Bright and CD14Dim cells. TF expression was significantly lower in pregnant women than in non-pregnant control subjects, on all CD14 positive cells at 20 and 35 weeks, on CD14Bright cells at 12 and 35 weeks and on CD14Dim cells at 20 weeks. Additionally, we report that a higher percentage of CD14Dim than CD14Bright cells express TF. These results suggest that, in order to maintain homeostasis in haemostasis in an otherwise hypercoagulable state, monocyte TF expression is reduced during normal pregnancy.
Heterogeneous Detection of A-antigen on von Willebrand Factor Derived from Platelets, Endothelial Cells and Plasma
Authors: Collins Peter , Bowen Derrick , Brown Simon 
Published: March 2018

SummaryThe exact function of the carbohydrate component of von Willebrand factor (VWF) is unknown. ABO blood group antigens are present as integral structures on the oligosaccharide side chains and it has long been recognised that ABO blood group is a determinant of VWF levels. The mechanism for this is not known. Using a monoclonal antibody against the A-antigen, we investigated the presence of this antigen on VWF from plasma, platelets, human umbilical vein endothelial cells (HUVEC) and saphenous vein endothelial cells. Initial studies on plasma VWF revealed that 23.5% of samples appeared to be negative for the A-antigen. This was shown to correlate with the A2 subtype of the A-antigen (p <0.01). Analysis of intracellular VWF from saphenous vein endothelial cells revealed low levels of A-antigen to be present in comparison to the corresponding plasma VWF. In contrast, VWF from platelets and HUVEC gave no detectable A-antigen. However, within 1 h of administration of DDAVP to type 1 VWD patients, there was a >2-fold increase in the A-antigen/VWF:Ag ratio for VWF in the plasma. In vitro experiments with serum N-acetlygalactosaminyltransferase failed to demonstrate any addition of A-antigen to platelet or HUVEC VWF. These data are consistent with heterogeneity in the content of A-antigen on VWF from different physiological compartments. Also, they are consistent with either a change in the A-antigen content of VWF after release from the intracellular compartment or a difference in the intracellular addition of A-antigen to VWF by endothelium from different vascular beds.
In Vivo Plasminogen Deficiency Reduces Fat Accumulation
Authors: Ellis Jill , Yuen Lawrence , Hoover-Plow Jane 
Published: March 2018

SummaryObesity and non-insulin dependent diabetes are associated with a decrease in fibrinolysis, which is mediated by the plasminogen system. The purpose of the current study was to investigate the role of the plasminogen system in the reduced body weight of the plasminogen deficient (Plg−/−) mice. In this study we have found that the reduced body weight in Plg−/− mice is due to a reduced rate of the adipose tissue (25% less) and whole body fat (30% less) accumulation during growth in Plg−/− compared to wild-type (WT) littermates. When the mice are fed a high fat-lipogenic diet, adipose tissue accumulation increases in the Plg−/− mice indicating that the capacity for lipid filling of cells was not blocked. In addition, glycerol phosphate dehydrogenase, a marker of late differentiation, was not different in the depots from WT and Plg−/− mice. The number of stromal cells (number × 105/g adipose tissue), isolated from inguinal (Plg−/− 3.4 ± 1.2, n = 6; WT 0.17 ± 0.07, n = 7, p < 0.02) and gonadal (Plg−/− 11.0 ± 0.4, n = 6; WT 3.1 ± 0.7, n = 7, p < 0.05) fat depots, was markedly higher in the depots from the Plg−/− mice than WT mice. Differentiation of stromal cells in culture from the Plg−/− mice was reduced compared to cells from WT mice. These results suggest that differences in the stromal cell population are responsible for the reduced adipose tissue accumulation in the Plg−/− mice, and that the plasminogen system plays an important role in adipose tissue accumulation.
An Additional Mechanism of Action of Abciximab: Dispersal of Newly Formed Platelet Aggregates
Authors: Marciniak Stanley , Furman Mark , Michelson Alan , Jakubowski Joseph , Jordan Robert , Marchese Peter , Frelinger Andrew , Mascelli Mary 
Published: March 2018

SummaryThe ability of abciximab to prevent fibrinogen binding to activated platelets indicates it may also promote dissolution of platelet-rich thrombi. The present study examined the capacity of abciximab to reverse platelet aggregation in vitro.
Experiments were performed on blood from healthy non-medicated donors. Platelet aggregate formation and disaggregation were monitored turbidimetrically. Platelet-bound fibrinogen was measured by flow cytometry. For disaggregation studies, platelets were first stimulated with either ADP or the 11-mer thrombin receptor activating peptide (TRAP), then varying amounts of abciximab were added at periodic intervals after agonist addition. Platelet disaggregation was detected by comparing the extent of light transmittance at 4 min after addition of either abciximab or saline to PRP. ATP release was simultaneously monitored by chemi-luminescence. When added 1 min after low concentrations of ADP, abciximab rapidly (<1 min) dispersed platelet aggregates in a dose-dependent manner, with complete disaggregation observed with 6.25 µg/mL of the β3 antagonist. In contrast, equivalent concentrations of abciximab did not induce appreciable disaggregation to platelets stimulated with TRAP (10 µM). Platelet counts of samples that had undergone complete disaggregation, as assessed by aggregometry, were equivalent to baseline, indicating dispersal of aggregates to single cells. Concentrations of abciximab that produced complete disaggregation induced partial displacement of platelet-bound fibrinogen (52 ± 8% inhibition of fibrinogen binding at 12.5 µg/ml abciximab). The disaggregation effectiveness of abciximab decreased as the time between ADP and subsequent abciximab addition widened, and as the amount of both dense granule release and agonist stimulation increased. However, pre-treatment of platelets with acetylsalicylic acid (ASA) did not potentiate platelet disaggregation induced by abciximab.These data indicate that abciximab facilitates the dispersal of newly formed platelet aggregates in vitro, by partially displacing fibrinogen from activated GPIIb/IIIa receptors. In vivo, abciximab may destabilize coronary thrombi by preventing aggregate formation and dispersing mural thrombi.
Selective Inhibition of Protease-activated Receptor 4-dependent Platelet Activation by YD-3
Authors: Wu Chin-Chung , Hwang Tsong-Long , Liao Chang-Hui , Kuo Sheng-Chu , Lee Fang-Yu , Lee Chun-Yann , Teng Che-Ming 
Published: March 2018

SummaryIn the present study, the antiplatelet effect and its mechanism of a new synthetic compound YD-3 [1-benzyl-3-(ethoxycarbonylphenyl)-indazole] were examined. YD-3 inhibited the aggregation of washed human platelets caused by protease-activated receptor (PAR) 4 agonist peptide GYPGKF (IC50 = 0.13 ± 0.02 µM), but had no or little effect on that by thrombin, PAR1 agonist peptide SFLLRN, collagen or U46619. YD-3 produced a parallel, rightward shift of the concentration-response curve for GYPGKF without decreasing of the maximum platelet aggregation, indicating a competitive antagonism. In contrast to human platelets, both thrombin- and GYPGKF-induced mouse platelet shape change and aggregation were completely inhibited by YD-3. YD-3 also selectively prevented GYPGKF-induced intracellular Ca2+ mobilization in human platelets. Furthermore, in the PAR1-desensitized human platelets, thrombin induced a relatively slow rise and decay of calcium mobilization that was significantly inhibited by YD-3. In addition, the synergistic effect of SFLLRN and GYPGKF on platelet activation was prevented by YD-3. YD-3 also inhibits both fMLP-stimulated neutrophil- and purified cathepsin G-induced platelet aggregation, which has been demonstrated to be PAR4-dependent. Taken together, our results suggest that YD-3 selectively inhibits PAR4-dependent platelet activation through blockade of PAR4. To the best of our knowledge, it is the first non-peptide PAR4 antagonist.