Adenosine Inhibits Tissue Factor Expression by LPS-stimulated Human Monocytes: Involvement of the A3 Adenosine Receptor

2002 ◽  
Vol 88 (07) ◽  
pp. 123-130 ◽  
Author(s):  
Matthieu Broussas ◽  
Pascale Cornillet-Lefèbvre ◽  
Gérard Potron ◽  
Philippe Nguyên
Keyword(s):  
Tissue Factor ◽  
Rank Order ◽  
Mrna Level ◽  
Dependent Manner ◽  
Human Monocytes ◽  
Extrinsic Pathway ◽  
A3 Adenosine Receptor ◽  
Factor Expression ◽  
Cardioprotective Effects ◽  
Dose Dependent

SummaryTissue Factor (TF), an integral membrane glycoprotein that initiates the extrinsic pathway of blood coagulation, is thought to play a major part in coronary acute events. Adenosine, an endogenous nucleoside produced by the degradation of intracellular adenosine triphosphate, has been shown to exert many cardioprotective effects via an inhibition of platelets and neutrophils. This study was conducted to determine whether adenosine (ADO) could modulate the expression of TF by human monocytes. We found that ADO inhibited TF antigen and activity on endotoxin-stimulated monocytes in a dose-dependent manner. The mechanism was at least pre-translational since ADO caused a change in the TF mRNA level. Using ADO receptor-specific analogs, we showed that highly selective A3 agonist N6-(3-iodobenzyl)-adenosine-5’-N’-methyluronamide (IB-MECA) inhibited LPSinduced TF activity expression more potently than A1 agonist R-phenylisopropyladenosine (R-PIA) and A2 agonist CGS 2180. Furthermore, A1/A3 antagonist, xanthine amine congener (XAC) blocked the effect of ADO whereas A2a, A2b and A1 antagonists were ineffective. In addition, we observed that ADO agonists inhibited monocyte TF expression in LPS-stimulated whole blood. The rank order of agonist potency suggested that A2 and A3 receptors might be involved (2-Cado > CGS = IB-MECA > R-PIA). This was supported by the fact that A2 and A3 antagonists reversed the action of 2-Cado. We conclude that TF inhibition by ADO on human purified monocytes involved A3 receptors.

AV513 Promotes Tissue Factor-Mediated Coagulation in Fresh Human Whole Blood from Severe and Moderate Hemophilia a Subjects.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1223-1223
Author(s):  
Jerry Sherman Powell ◽  
Sabine Knappe ◽  
Janet A Harrison ◽  
Susannah Patarroyo-White ◽  
Kirk Johnson ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Whole Blood ◽  
Thrombin Generation ◽  
Hemophilia A ◽  
Lag Phase ◽  
Dependent Manner ◽  
Normal Range ◽  
Extrinsic Pathway ◽  
Maximum Increase ◽  
Dose Dependent

Abstract The sulfated polysaccharide extract AV513 accelerates effective clotting of plasma from severe hemophilia A and B subjects, primarily through the extrinsic pathway by inhibiting TFPI activity. AV513 is efficacious in normalizing bleeding times in hemophilia A dogs when administered orally or subcutaneously, either alone or in the presence of very low levels of factor VIII. In this report, we have examined the effects on hemostasis of different concentrations of AV513 (0.25 to 5 ug/mL) added to fresh whole blood from eight severe (FVIII <1 %) and four moderate (FVIII 3–5 %) hemophilia A subjects. Blood was drawn on two separate occasions, 30 days apart, from each subject after receiving no FVIII infusion for 5 days and analyzed using tissue factor-triggered whole blood thromboelastography (TEG) and plasma based thrombin generation assay. In the tissue factor-induced TEG assay, AV513 reduced the whole blood R time (time to initial clot formation) of severe and moderate human hemophilia A blood in a dose dependent manner. The R time values were corrected to the normal range (≤ 27 min) at AV513 concentrations of 0.25 to 1 ug/mL in blood from both severe and moderate hemophilia A subjects. The TEG EC50 (AV513 concentration that reduces R time by 50% from baseline) values were approximately 0.7 ug/mL in both cohorts. Based on two TEG determinations for each subject, the intra-subject baseline variability of whole blood R time had a range of 3–19 % (mean: 10 %) for severe and 2–16 % (mean: 8 %) for moderate subjects. The intersubject baseline R time value varied from 29 to 91 min in the severe group and from 30 to 43 min in the moderate hemophilia A group. Further, an AV513 dose dependent increase in thrombin generation was observed in hemophilia A plasma with maximal thrombin peaks of 52 to 216 nM (mean: 110 nM). For all subjects, we observed a 2–4 fold maximum increase in thrombin peak and a 2–3 fold reduction of both the lag phase time and time to peak thrombin generation.. The EC50 values for peak thrombin generation were 0.2 ± 0.15 ug/mL and 0.7 ± 0.3 ug/mL of AV513 in severe and moderate hemophilia A plasma, respectively. These results demonstrate that AV513 in whole blood from severe and moderate hemophilia A subjects effectively shortened R time in the TEG assay to within the normal range, and that AV513 markedly enhanced thrombin generation in plasma from these subjects. These studies suggest that AV513 may prove useful to promote clotting and prevent spontaneous bleeding in clinical trials for patients with hemophilia A.

Local Anesthetics Inhibit Tissue Factor Expression in Activated Monocytes via Inhibition of Tissue Factor mRNA Synthesis

2010 ◽  
Vol 17 (6) ◽  
pp. E4-E9 ◽  
Author(s):  
Ji-Eun Kim ◽  
Ki Jun Kim ◽  
Wonsik Ahn ◽  
Kyou-Sup Han ◽  
Hyun Kyung Kim
Keyword(s):  
Tissue Factor ◽  
Local Anesthetics ◽  
Messenger Rna ◽  
Mrna Level ◽  
Dependent Manner ◽  
Tissue Factor Expression ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Factor Expression ◽  
Activated Monocytes

Local anesthetics have been reported to have anticoagulant properties, but the mechanisms responsible for this action are poorly understood. Here, we evaluated the in vitro effects of 3 local anesthetics—lidocaine, ropivacaine, and bupivacaine—on the tissue factor expression by monocytes. Monocytes from peripheral blood were stimulated with lipopolysaccharide (LPS) in the presence or absence of local anesthetics. All 3 local anesthetics inhibited the expression of tissue factor antigen and tissue factor activity in LPS-stimulated monocytes in a dose- and time-dependent manner and reduced tissue factor messenger RNA (mRNA) expression in endothelial cells and a monocytic cell line. None of the 3 drugs induced apoptosis or affected the viability of monocytes. Our findings that local anesthetics inhibited the tissue factor induction in activated monocytes by inhibiting tissue factor mRNA level may demonstrate the feasibility of using local anesthetics in hypercoagulable and inflammatory conditions.

Endotoxin-Induced Tissue Factor in Human Monocytes is Dependent upon Protein Kinase C Activation

1993 ◽  
Vol 70 (05) ◽  
pp. 800-806 ◽  
Author(s):  
C Ternisien ◽  
M Ramani ◽  
V Ollivier ◽  
F Khechai ◽  
T Vu ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tissue Factor ◽  
Factor Ix ◽  
Transcriptional Level ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Human Monocytes ◽  
Kinase C ◽  
Pkc Activation

SummaryTissue factor (TF) is a transmembrane receptor which, in association with factors VII and Vila, activates factor IX and X, thereby activating the coagulation protease cascades. In response to bacterial lipopolysaccharide (LPS) monocytes transcribe, synthesize and express TF on their surface. We investigated whether LPS-induced TF in human monocytes is mediated by protein kinase C (PKC) activation. The PKC agonists phorbol 12- myristate 13-acetate (PMA) and phorbol 12, 13 dibutyrate (PdBu) were both potent inducers of TF in human monocytes, whereas 4 alpha-12, 13 didecanoate (4 a-Pdd) had no such effect. Both LPS- and PMA-induced TF activity were inhibited, in a concentration dependent manner, by three different PKC inhibitors: H7, staurosporine and calphostin C. TF antigen determination confirmed that LPS-induced cell-surface TF protein levels decreased in parallel to TF functional activity under staurosporine treatment. Moreover, Northern blot analysis of total RNA from LPS- or PMA-stimulated monocytes showed a concentration-dependent decrease in TF mRNA levels in response to H7 and staurosporine. The decay rate of LPS-induced TF mRNA evaluated after the arrest of transcription by actinomycin D was not affected by the addition of staurosporine, suggesting that its inhibitory effect occurred at a transcriptional level. We conclude that LPS-induced production of TF and its mRNA by human monocytes are dependent on PKC activation.

Abstract 272: Sex Differences in β-Adrenergic Responsiveness of Excitation-Contraction Coupling in Isolated Rabbit Hearts

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Gregory Hoeker ◽  
Ashleigh Hood ◽  
Rodolphe Katra ◽  
Steven Poelzing ◽  
Steven Pogwizd
Keyword(s):  
Sex Differences ◽  
Action Potentials ◽  
Adrenergic Receptor ◽  
Calcium Release ◽  
Dependent Manner ◽  
Ectopic Activity ◽  
Dose Threshold ◽  
Ectopic Beats ◽  
Cardioprotective Effects ◽  
Dose Dependent

Introduction: Sex differences in β-adrenergic receptor (β-AR) responsiveness are associated with female cardioprotection. We hypothesize that female (F) rabbits have reduced responsiveness to β-AR stimulation vs males (M), and that the degree and type of sex differences vary with the β-AR subtypes that are activated. Methods: Ventricular action potentials (AP) and intracellular calcium transients (CaT) were optically mapped from the epicardial surface of rabbit hearts during 3 Hz pacing. Spontaneous calcium release (SCR) and ectopic activity were elicited at 1, 3, and 5.5 Hz. β-responsiveness was assessed with the nonselective β-agonist isoproterenol (Iso, 1-316 nM), or β2-AR selective agonist zinterol (Zin, 10 nM). Results: At baseline, the time constant of CaT decay (τ) was faster in F than M (54.0±1.7 vs 62.1±3.0 ms; n=14, 14; p < 0.05), with no sex difference in CaT duration (CaD80). AP duration (APD90) was shorter in F than M (202.5±5.0 vs 218.2±5.7 ms; p < 0.05). Iso decreased τ, CaD80, and APD90 in a dose-dependent manner in both sexes (n = 5, 5 for F, M). Iso decreased τ to a lesser extent in F than M for 1 and 32-316 nM Iso (F = 11-32 ms, M = 23-48 ms; p < 0.05). The Iso-induced decrease in CaD80 was not significantly different in F than M at any dose. The Iso-induced decrease in APD90 was significantly less in F than M only at 316 nM Iso (75.5±8.7 ms vs 103.9±6.2 ms, p < 0.05). In contrast, there were no sex differences in the response to Zin for τ, CaD80, or APD90 (n = 6, 6 for F, M). Zin decreased τ by 7.2±2.0 ms in F vs 12.7±3.7 ms in M; CaD80 by 18.0±5.3% in F vs 21.1±8.0 ms in M; and APD90 by 24.9±8.5 ms in F vs 21.9±8.9 ms in M. SCR was observed in 50% (6/12) of hearts treated with Zin, whereas Iso elicited SCR in all hearts (10/10) with a dose threshold of 32 nM. No ectopic beats were observed with Zin (0/36 trials in 12 hearts). With Iso, ectopic activity was less frequent in F hearts (16%, 12/75 trials in 5 hearts) than in M hearts (41%, 26/68 trials in 5 hearts, p < 0.05). Conclusions: These results suggest that sex differences in AP and CaT depend on the dose of the agonist used and the β-AR subtypes that are activated. Elucidating nuances of sex differences in β-AR subtype physiology will provide a better understanding of the mechanisms of reduced β-responsiveness in F and its cardioprotective effects.

Dexamethasone-Induced Apoptosis of Human Monocytes Exposed to Immune Complexes. Intervention of CD95-and Xiap-Dependent Pathways

2005 ◽  
Vol 18 (3) ◽  
pp. 403-415 ◽  
Author(s):  
L. Ottonello ◽  
M. Bertolotto ◽  
F. Montecucco ◽  
P. Dapino ◽  
F. Dallegri
Keyword(s):  
Immune Complex ◽  
Immune Complexes ◽  
Therapeutic Option ◽  
Mek Inhibitor ◽  
Dependent Manner ◽  
Human Monocytes ◽  
Inflammatory Reactions ◽  
Activated Monocytes ◽  
Induced Apoptosis ◽  
Dose Dependent

Monocytes and macrophages play a key role in the initiation and persistence of inflammatory reactions. The possibility to interfere with the survival of these cells, once recruited and activated at sites of inflammation, is an attractive therapeutic option. Although resting monocytes are susceptible to pharmacologically induced apoptosis, no data are available about the possibility to modulate the survival of activated monocytes. The present work was planned to investigate if dexamethasone is able to promote apoptosis of human monocytes activated by immune complexes. When monocytes were cultured with immune complexes, a dose-dependent inhibition of apoptosis was observed. Dexamethasone stimulated apoptosis of resting and activated monocytes in a dose-dependent manner. Both the immune complex inhibitory activity and dexamethasone stimulatory properties depend on NF-kB/XIAP and Ras/MEK/ERK/CD95 pathways. In fact, the exposure of monocytes to immune complexes increased NF-kB activation and XIAP expression, which in turn were inhibited by dexamethasone. On the other hand, immune complex-stimulated monocytes displayed a reduced expression of CD95, which is prevented by dexamethasone, as well as by MEK inhibitor U0126. Furthermore, anti-CD95 ZB4 mAb prevented dexamethasone-induced apoptosis in immune complex-stimulated monocytes. Similarly, ZB4 inhibited dexamethasone-mediated augmentation of caspase 3 activity. The present findings suggest that Fc triggering by insoluble immune complexes result in the activation of two intracellular pathways crucial for the survival of monocytes: 1. Ras/MEK/ERK pathway responsible for the down-regulation of CD95 expression; 2. NF-kB pathway governing the expression of XIAP. Both the pathways are susceptible to inhibition by monocyte treatment with pharmacologic concentrations of dexamethasone.

LUMI-AGGREGOMETER STUDIES OF THE INITIAL ATP-SECRETION FROM COLLAGEN-ADHERENT PLATELETS

1987 ◽  
Author(s):  
R Malmgren
Keyword(s):  
Platelet Adhesion ◽  
Rank Order ◽  
Shape Change ◽  
Dense Granule ◽  
Dependent Manner ◽  
Equal Degree ◽  
Atp Secretion ◽  
Ic50 Values ◽  
Dose Dependent ◽  
Platelet Shape

We have earlier, with the use of a lumi-aggregometer and sub-aggregating doses of collagen (0.2-0.8 ug/ml PRP), been able to detect the initial, aspirin-insensitive secretion of ATP from the collagen-adherent platelets, and to correlate this secretion to the doses of collagen, and onset and degree of subsequent shape change of non-adherent platelets (Malmgren, Thromb Res 4:445, 1986). The present study shows, that 200 ATU of hirudin,which reduced near-maximal aggregation and ATP-secretion induced by high collagen doses (2.5 ug/ml PRP) from 3.35 ± 0.2 uM to 2.85 ± 0.1 uM, did neither reduce the secreted amount of ATP that were 82.5 ± 15 nM in control samples and 90 ± 27.5 nM in hirudin-treated samples, nor reduce platelet shape change when platelets were challenged with 0.31 ug collagen /ml PRP. (200 ATU hirudin completely abolished an equal degree of platelet shape change induced by 0.01 U thrombin). Assuming that 3 % of the platelets in PRP were actually adhering to the collagen fibrils, the secreted amount corresponds to 14.6 ±0.04 pmoles ATP/106adheringplatelets, amounts which closely represented 100 % of their dense granule content. The finding confirms that hirudin does not inhibit platelet adhesion and also indicates, that thrombin-mediated activation of secretory pathways appears not to be involved during the initial phase of platelet-collagen interactions.Dipyridamole (DPA) and dibutyryl cAMP (DBcAMP) inhibited ATP-secretion and platelet aggregation in a dose-dependent manner at high collagen concentrations, but only DBcAMP caused a dose-dependent reduction of ATP secretion (IC50 =10-4 M) induced by sub-aggregating doses of collagen. DPA was devoid of effect in this respect and thus did not inhibit platelet adhesion.Yohimbine, dihydroergotamine and phentolamine reduced ATP-secretion induced by sub-aggregating collagen doses in the mentioned rank order of potency, and with IC50 values in the micromolar range. Ketanserin, ritanserin and propranolol were devoid of effect. The findings suggest that the initial collagen-plate-let interaction involve alfareceptor-mediated mechanisms that may encompass adhesion, while DBcAMP probably interacts with secretory mechanisms connected to phosphatidylinositol turnover.

scholarly journals Neutrophils: back in the thrombosis spotlight

Blood ◽  
2019 ◽  
Vol 133 (20) ◽  
pp. 2186-2197 ◽  
Author(s):  
Denis F. Noubouossie ◽  
Brandi N. Reeves ◽  
Brian D. Strahl ◽  
Nigel S. Key
Keyword(s):  
Animal Models ◽  
Tissue Factor ◽  
Contact System ◽  
Neutrophil Extracellular Trap ◽  
Human Neutrophils ◽  
Dependent Manner ◽  
Extrinsic Pathway ◽  
Vessel Occlusion ◽  
Activated Neutrophils

Abstract Reactive and clonal neutrophil expansion has been associated with thrombosis, suggesting that neutrophils play a role in this process. However, although there is no doubt that activated monocytes trigger coagulation in a tissue factor-dependent manner, it remains uncertain whether stimulated neutrophils can also directly activate coagulation. After more than a decade of debate, it is now largely accepted that normal human neutrophils do not synthetize tissue factor, the initiator of the extrinsic pathway of coagulation. However, neutrophils may passively acquire tissue factor from monocytes. Recently, the contact system, which initiates coagulation via the intrinsic pathway, has been implicated in the pathogenesis of thrombosis. After the recent description of neutrophil extracellular trap (NET) release by activated neutrophils, some animal models of thrombosis have demonstrated that coagulation may be enhanced by direct NET-dependent activation of the contact system. However, there is currently no consensus on how to assess or quantify NETosis in vivo, and other experimental animal models have failed to demonstrate a role for neutrophils in thrombogenesis. Nevertheless, it is likely that NETs can serve to localize other circulating coagulation components and can also promote vessel occlusion independent of fibrin formation. This article provides a critical appraisal of the possible roles of neutrophils in thrombosis and highlights some existing knowledge gaps regarding the procoagulant activities of neutrophil-derived extracellular chromatin and its molecular components. A better understanding of these mechanisms could guide future approaches to prevent and/or treat thrombosis.

TGF-β1 Induces Tissue Factor Expression in Human Lung Fibroblasts in a PI3K/JNK/Akt-Dependent and AP-1–Dependent Manner

2012 ◽  
Vol 47 (5) ◽  
pp. 614-627 ◽  
Author(s):  
Malgorzata Wygrecka ◽  
Dariusz Zakrzewicz ◽  
Brigitte Taborski ◽  
Miroslava Didiasova ◽  
Grazyna Kwapiszewska ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Human Lung ◽  
Lung Fibroblasts ◽  
Dependent Manner ◽  
Tissue Factor Expression ◽  
Human Lung Fibroblasts ◽  
Factor Expression ◽  
Tgf Β1

scholarly journals Tissue Factor Expression of Human Monocytes Is Suppressed by Lysophosphatidylcholine

1999 ◽  
Vol 19 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Bernd Engelmann ◽  
Susanne Zieseniss ◽  
Korbinian Brand ◽  
Sharon Page ◽  
Arnd Lentschat ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Human Monocytes ◽  
Tissue Factor Expression ◽  
Factor Expression

scholarly journals Inhibition of swarming and virulence factor expression in Proteus mirabilis by resveratrol

2006 ◽  
Vol 55 (10) ◽  
pp. 1313-1321 ◽  
Author(s):  
Won-Bo Wang ◽  
Hsin-Chih Lai ◽  
Po-Ren Hsueh ◽  
Robin Y.-Y. Chiou ◽  
Shwu-Bin Lin ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Virulence Factor ◽  
Proteus Mirabilis ◽  
Antioxidant Activities ◽  
Dependent Manner ◽  
Urothelial Cells ◽  
Defective Mutant ◽  
Two Component ◽  
Factor Expression ◽  
Dose Dependent

Resveratrol (3,5,4-trihydroxy-trans-stilbene) is a phytoalexin compound with anti-inflammatory and antioxidant activities. The effect of resveratrol on swarming and virulence factor expression of Proteus mirabilis, an important pathogen infecting the urinary tract, was determined on swarming agar plates with and without the compound. Bacteria harvested at different times were assayed for cell length and the production of flagella, haemolysin and urease. Resveratrol inhibited P. mirabilis swarming and virulence factor expression in a dose-dependent manner. Resveratrol significantly inhibited swarming at 15 μg ml−1, and completely inhibited swarming at 60 μg ml−1. Inhibition of swarming and virulence factor expression was mediated through RsbA, a His-containing phosphotransmitter of the bacterial two-component signalling system possibly involved in quorum sensing. Complementation of an rsbA-defective mutant with the rsbA gene restored its responsiveness to resveratrol. The compound also inhibited the ability of P. mirabilis to invade human urothelial cells. These findings suggest that resveratrol has potential to be developed as an antimicrobial agent against P. mirabilis infection.

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