INTRAVENOUS BACTERIAL LIPOPOLYSACCHARIDE IMPAIRS MONOCYTE TISSUE FACTOR GENERATION IN RABBITS

1987 ◽  
Author(s):  
R Edwards ◽  
W Brande
Keyword(s):  
New Zealand ◽  
Tissue Factor ◽  
Blood Coagulation ◽  
Mononuclear Cell ◽  
Suppressor Activity ◽  
Arterial Blood ◽  
New Zealand White Rabbits ◽  
Mo Content

Bacterial 1ipopolysaccharide (LPS) ts a potent stimulus for monocyte tissue factor (MTF) generation jn. vitro. We have examined the effect of small amounts of LPS on MTF expression in vivo. LPS (0.1 - 50ug) was injected into the ear veins of 66 New Zealand White rabbits. Arterial blood was collected immediately prior to LPS (TO), and 5 (T5) and 30 (T30) minutes later. Mononuclear cell suspensions (MC) were assessed for monocyte (Mo) content and MTF generation was determined in both unstimulated and LPS-stimulated MC cultures (18 hours incubation). As seen in the table, T5 cells obtained following in vivo exposure to 5 or lOug LPS demonstrated spontaneous MTF generation in the absence of in vitro stimulation. By T30, the Mo content of MC decreased from 28% to 17% and MTF generation was decreased in both stimulated and unstimulated cultures. However, this decreased MTF could not be explained by reduction in Mo number. In reconstitution experiments, T30 lymphoctes (Ly) did not suppress TO MTF generation and TO Ly did not restore T30 MTF generation, suggesting that the decreased MTF generation is not mediated by increased Ly suppressor activity. Neither heparin, warfarin nor hydrocortisone had any effect on Mo count or on MTF generation. These experiments suggest that small amounts of LPS activate a subpopulation of Mo, which is quickly lost from the circulation, while the remaining Mo are resistant to further LPS stimulation. Direct activation of this subpopulation of competent Mo by LPS may contribute to activation of blood coagulation in sepsis.

scholarly journals Tissue factor–positive neutrophils bind to injured endothelial wall and initiate thrombus formation

Blood ◽  
2012 ◽  
Vol 120 (10) ◽  
pp. 2133-2143 ◽  
Author(s):  
Roxane Darbousset ◽  
Grace M. Thomas ◽  
Soraya Mezouar ◽  
Corinne Frère ◽  
Rénaté Bonier ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Tissue Factor ◽  
Blood Coagulation ◽  
Thrombus Formation ◽  
Coagulation Cascade ◽  
Factor Xii ◽  
Long Time ◽  
Platelet Accumulation

AbstractFor a long time, blood coagulation and innate immunity have been viewed as interrelated responses. Recently, the presence of leukocytes at the sites of vessel injury has been described. Here we analyzed interaction of neutrophils, monocytes, and platelets in thrombus formation after a laser-induced injury in vivo. Neutrophils immediately adhered to injured vessels, preceding platelets, by binding to the activated endothelium via leukocyte function antigen-1–ICAM-1 interactions. Monocytes rolled on a thrombus 3 to 5 minutes postinjury. The kinetics of thrombus formation and fibrin generation were drastically reduced in low tissue factor (TF) mice whereas the absence of factor XII had no effect. In vitro, TF was detected in neutrophils. In vivo, the inhibition of neutrophil binding to the vessel wall reduced the presence of TF and diminished the generation of fibrin and platelet accumulation. Injection of wild-type neutrophils into low TF mice partially restored the activation of the blood coagulation cascade and accumulation of platelets. Our results show that the interaction of neutrophils with endothelial cells is a critical step preceding platelet accumulation for initiating arterial thrombosis in injured vessels. Targeting neutrophils interacting with endothelial cells may constitute an efficient strategy to reduce thrombosis.

Polymorphonuclear leukocyte cytoplasts mediate acute lung injury

1988 ◽  
Vol 65 (2) ◽  
pp. 706-713 ◽  
Author(s):  
V. B. Antony ◽  
C. L. Owen ◽  
D. English
Keyword(s):  
Acute Lung Injury ◽  
New Zealand ◽  
Lung Injury ◽  
Polymorphonuclear Leukocyte ◽  
Lung Lavage ◽  
Lung Weight ◽  
Endothelial Monolayers ◽  
New Zealand White Rabbits

Injection of phorbol 12-myristate 13-acetate (PMA) into polymorphonuclear leukocyte (PMN)-depleted, PMN cytoplast-repleted New Zealand White rabbits caused the development of acute lung injury in vivo. PMN cytoplasts are nucleus- and granule-free vesicles of cytoplasm capable of releasing toxic O2 radicals but incapable of releasing granule enzymes. PMN cytoplasts when activated by PMA reduced 66 +/- 12.7 nmol of cytochrome c compared with 2.6 +/- 0.7 nmol in their resting state and did not release a significant quantity of granule enzymes (P greater than 0.05). Injection of PMA into New Zealand White rabbits caused a significant decrease (P less than 0.05) in the number of circulating cytoplasts. Increases in lung weight-to-body weight ratios in PMA-treated rabbits (9.8 +/- 0.5 X 10(-3] compared with saline-treated rabbits (5.3 +/- 0.2 X 10(-3] were also noted. Levels of angiotensin-converting enzyme in lung lavage as well as the change in alveolar-arterial O2 ratio correlated with the numbers of cytoplasts in lung lavage (P = 0.001, r = 0.84 and P = 0.0166, r = 0.73, respectively). Albumin in lung lavage increased to 1,700 +/- 186 mg/ml in PMA-treated rabbits from 60 +/- 30 mg/ml in saline-treated rabbits. These changes were attenuated by pretreatment of rabbits with dimethylthiourea (DMTU). In vitro, cytoplasts were able to mediate increases in endothelial monolayer permeability. This was evidenced by increases in fractional transit of albumin across endothelial monolayers when treated with PMA-activated cytoplasts (0.08 +/- 0.01 to 0.28 +/- 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-35 promotes early endothelialization after stent implantation by regulating macrophage activation

2019 ◽  
Vol 133 (7) ◽  
pp. 869-884 ◽  
Author(s):  
Xianglan Liu ◽  
Ruoxi Zhang ◽  
Jingbo Hou ◽  
Jian Wu ◽  
Maomao Zhang ◽  
...  
Keyword(s):  
New Zealand ◽  
Cross Sections ◽  
Inflammatory Responses ◽  
Umbilical Vein ◽  
Neointimal Hyperplasia ◽  
Macrophage Phenotype ◽  
New Zealand White Rabbits ◽  
Anti Inflammatory

Abstract Background: Early strut coverage after sirolimus-eluting stent (SES) implantation is associated with the activation of inflammation, but the underlying mechanisms are not completely understood. The present study aimed to identify the relationship between the anti-inflammatory cytokine interleukin (IL) 35 (IL-35) and early strut coverage in vivo and in vitro. Methods: We utilized a retrospective study design to measure IL-35 levels in 68 stents from 68 patients with coronary artery disease and recorded serial optical coherence tomography (OCT) images (0 and 3 months) to assess stent endothelialization. The mechanism underlying the regulatory effects of IL-35 on macrophages and human umbilical vein endothelial cells (HUVECs) was also investigated. SESs were surgically implanted into the right common carotid arteries of 200 male New Zealand White rabbits receiving intravenous injections of IL-35 or a placebo. Results: At the 3-month OCT evaluation, complete endothelium coverage was correlated with IL-35 levels. IL-35 induced the activation of an anti-inflammatory M2-like macrophage phenotype by targeting the signal transducer and activators of transcription (STAT)1/4 signalling pathway, and IL-35-treated macrophages induced endothelial proliferation and alleviated endothelial dysfunction. IL-35-treated New Zealand White rabbits with implanted SESs showed lower percentages of cross-sections with an uncovered strut, elevated mean neointimal hyperplasia (NIH) thickness, and inhibited inflammatory responses. Conclusions: We investigated the effect of IL-35 expression on early stent endothelialization in vivo and in vitro and identified a crucial role for IL-35 in inducing the activation of an anti-inflammatory M2-like macrophage phenotype. The present study highlights a new therapeutic strategy for early stent endothelialization.

scholarly journals Mononuclear cell tissue factor: cell of origin and requirements for activation

Blood ◽  
1979 ◽  
Vol 54 (2) ◽  
pp. 359-370 ◽  
Author(s):  
RL Edwards ◽  
FR Rickles ◽  
AM Bobrove
Keyword(s):  
Tissue Factor ◽  
Mononuclear Cell ◽  
Mononuclear Leukocytes ◽  
Cell Of Origin ◽  
Cell Tissue ◽  
Cell Subpopulations ◽  
The Relationship ◽  
Human Mononuclear Leukocytes

Abstract Human mononuclear leukocytes generate the procoagulant material tissue factor (TF) following stimulation by endotoxin, mitogens, or antigens in vitro. We have examined tissue-factor generation by mononuclear cell subpopulations prepared in a variety of ways in order to determine the cell of origin of mononuclear cell TF and the conditions necessary for maximal in vitro TF generation. We have also examined the relationship between in vitro TF generation and in vivo or in vitro measures of delayed hypersensitivity in response to identical antigen stimulation. Our results demonstrate that the monocyte is responsible for the bulk of mononuclear cell TF generation in vitro and that adhesion alone is not sufficient stimulation for significant.

Bioreactor optimization of tissue engineered rabbit flexor tendons in vivo

2012 ◽  
Vol 37 (2) ◽  
pp. 109-114 ◽  
Author(s):  
J. Thorfinn ◽  
I. K. Angelidis ◽  
L. Gigliello ◽  
H. M. Pham ◽  
D. Lindsey ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
New Zealand ◽  
Ultimate Tensile Strength ◽  
Cyclic Strain ◽  
Flexor Tendons ◽  
New Zealand White Rabbits ◽  
Zone Ii

Tissue-engineered rabbit flexor tendons reseeded with cells are stronger in vitro after culture in a bioreactor. It is not known whether this effect persists in vivo. Tenocytes from New Zealand white rabbits were seeded onto rabbit rear paw flexor tendons that were deprived of cells and exposed to cyclic strain in a bioreactor. Reseeded constructs that were kept unloaded in a medium for 5 days were used as controls. The tendons were implanted to bridge a zone II defect in the rabbit. After explantation 4 weeks later, the ultimate tensile strength (UTS) and elastic modulus (EM) were determined. Tendon constructs that were exposed to cyclic strain had significantly improved UTS and EM. Histology showed that cellularity was increased in the bioreactor tendons.

scholarly journals Mononuclear cell tissue factor: cell of origin and requirements for activation

Blood ◽  
1979 ◽  
Vol 54 (2) ◽  
pp. 359-370 ◽  
Author(s):  
RL Edwards ◽  
FR Rickles ◽  
AM Bobrove
Keyword(s):  
Tissue Factor ◽  
Mononuclear Cell ◽  
Mononuclear Leukocytes ◽  
Cell Of Origin ◽  
Cell Tissue ◽  
Cell Subpopulations ◽  
The Relationship ◽  
Human Mononuclear Leukocytes

Human mononuclear leukocytes generate the procoagulant material tissue factor (TF) following stimulation by endotoxin, mitogens, or antigens in vitro. We have examined tissue-factor generation by mononuclear cell subpopulations prepared in a variety of ways in order to determine the cell of origin of mononuclear cell TF and the conditions necessary for maximal in vitro TF generation. We have also examined the relationship between in vitro TF generation and in vivo or in vitro measures of delayed hypersensitivity in response to identical antigen stimulation. Our results demonstrate that the monocyte is responsible for the bulk of mononuclear cell TF generation in vitro and that adhesion alone is not sufficient stimulation for significant.

Antibodies to β2-Glycoprotein I Associated with Antiphospholipid Syndrome Suppress the Inhibitory Activity of Tissue Factor Pathway Inhibitor

2000 ◽  
Vol 84 (10) ◽  
pp. 653-656 ◽  
Author(s):  
Irene Salemink ◽  
Ron Blezer ◽  
George Willems ◽  
Monica Galli ◽  
Edouard Bevers ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Blood Coagulation ◽  
Tissue Factor Pathway Inhibitor ◽  
Factor Xa ◽  
Anionic Phospholipid ◽  
Normal Plasma ◽  
Increased Risk ◽  
Tissue Factor Pathway

SummaryAnionic phospholipid membranes have a dual role in blood coagulation: they are essential for the initiation and propagation as well as for the limitation and termination of the blood coagulation process. Patients with the anti-phospholipid syndrome (APS) carrying antibodies against complexes of anionic phospholipids and plasma proteins, show in vitro inhibited phospholipid dependent coagulation reactions, whereas in vivo the presence of these antibodies is associated with an increased risk of thrombosis. In this study we focussed on the effects of these anti-phospholipid antibodies on the regulation of TF-mediated factor Xa (FXa) generation in plasma. We hypothesized that anti-phospholipid antibodies interfere with the phospholipiddependent inhibition by tissue factor pathway inhibitor (TFPI) of TFinduced coagulation. Indeed, total-IgG, anti-cardiolipin-IgG (aCL) and anti-β2GPI-IgG, isolated from patient plasmas, all stimulated TF-induced FXa generation in normal plasma. This enhanced FXa generation was not observed when the patient’s IgG was depleted of anti-β2GPI-IgG or when normal plasma was depleted of β2GPI or TFPI. Taken together, these data indicate that antibodies to β2GPI, circulating in patients with APS, suppress TFPI-dependent inhibition of TF-induced coagulation, which results in an increased FXa generation.

Demystifying Tissue Factor.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 1936-1936 ◽  
Author(s):  
Saulius Butenas ◽  
Matthew T. Gissel ◽  
Beth A. Bouchard ◽  
Kathleen E. Brummel ◽  
Behnaz Parhami-Seren ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Blood Coagulation ◽  
Whole Blood ◽  
Thrombin Generation ◽  
Factor Viia ◽  
Integral Membrane Protein ◽  
Factor X ◽  
Initiation Phase

Abstract Tissue factor (TF) is an integral membrane protein, which is the key initiator of blood coagulation in vivo. Due to the limited availability of natural TF, recombinant proteins of various lengths and origins have been extensively used in research and clinical laboratories worldwide. Experimental results acquired with recombinant TF proteins are frequently used for the understanding of the coagulation processes occurring in vivo, although there is a lack of data confirming the structural and functional identity of natural TF proteins from various sources and recombinant ones. In the current study, human TF from cultured monocytes and purified from placenta were compared with three different species of recombinant TF: 1–218 (extracellular domain only), 1–242 (lacking cytoplasmic domain) and 1–263 (full-length). Anti-TF mAbs gave 93–98% inhibition of TF activity for all TF species tested, in both natural and relipidated preparations. It was established that purified placental TF has a higher affinity for factor VIIa (Kd 0.13 nM) than recombinant counterparts 1–242 and 1–263 (Kd 0.50–0.80 nM). Similarly, placental TF is more efficient in factor X activation by the extrinsic Xase than recombinant TF 1–242 (the second order rate constants are 3.0x107 and 0.7x107 M−1s−1, respectively). We explored the use of these TF species as well as monocyte TF (purified/relipidated and present on LPS-stimulated monocytes) for the initiation of thrombin generation in two in vitro models of blood coagulation. At equimolar concentrations (5 pM; determined by immunoassay), when evaluated in synthetic plasma reconstituted with 2x108/ml platelets, recombinant TF 1-263 provided an initiation phase of ~4 min. Placental TF and relipidated monocyte TF had similar profiles of thrombin generation with an initiation phase of ~3 min. In contrast, 0.5 pM TF on LPS-stimulated monocytes gave an initiation phase of ~1 min. Even at 0.05 pM concentration, monocyte TF was as active as any relipidated protein at 5.0 pM. A similar pattern of relative TF activity was observed in whole blood and plasma PT clotting assays. TF on stimulated monocytes gave the highest activity, exceeding that of any relipidated protein by 100–200-fold. Recombinant TF 1–242 was more active than recombinant TF 1–263 and placental TF in the PT assay but less active in synthetic plasma and whole blood. The lowest overall activity was observed for relipidated monocyte TF. Our data suggest that TF proteins from different sources are different with respect to their functional properties.

Interactions of Factor VIII with Tissue Factor Contributes to the Acceleration of Factor Xa Generation in the Initiation Phase of Blood Coagulation.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3177-3177
Author(s):  
Kenichi Ogiwara ◽  
Keiji Nogami ◽  
Masahiro Okuda ◽  
Katsumi Nishiya ◽  
Masahiro Takeyama ◽  
...  
Keyword(s):  
Tissue Factor ◽  
Blood Coagulation ◽  
Factor Xa ◽  
Initiation Phase ◽  
Prothrombinase Complex ◽  
Fviii Activity ◽  
Actual Increase ◽  
Tissue Factor Pathway

Abstract Abstract 3177 Poster Board III-116 Activated factor (F)VII complex with tissue factor (FVIIa/TF) initiates the blood coagulation by generating FXa as extrinsic Xase complex (ex-Xase). Although FVIIa/TF also activates FIX, FIXa little functions without its cofactor, FVIIIa. A tiny amount of thrombin generated by FXa activates FV and FVIII, followed by forming of intrinsic Xase complex (in-Xase) and prothrombinase complex, respectively. These formations result in ‘thrombin burst’ and successful hemostasis. Although thrombin is thought to be a unique potent activator of FVIII in vivo, FXa and FVIIa/TF also activate FVIII in vitro. We have recently reported the detailed mechanism by which FVIIa/TF activated FVIII more rapidly in early timed-phase than thrombin (Blood Abst.1036, 2008). In this study, we further developed to examine whether TF affected FVIII(a) function. (1) FVIIa/TF rapidly increased FVIII activity by 4.7-fold of initial in the presence of Ca2+ and phospholipid (PL), following by inactivation, in one-stage clotting assay. However, since even in the presence of TF alone, FVIII activity elevated by 1.8-fold of initial, actual increase of FVIII activity by FVIIa/TF was 2.6-fold. A possibility that TF might bind to FVIIa contained in FVIII-deficient plasmas used, was negligible, since FVIIa-inhibitor used blocked an ex-Xase effect >95%. In the presence of FVIIa-inhibitor, residue FVIII activity with TF was ∼50%, thus TF alone affected FVIII cofactor activity independently of FVIIa. (2) Using SDS-PAGE, the addition of TF accelerated FVIII cleavage by FVIIa, whilst decelerated that by thrombin and FXa. (3) Surface plasmon resonance-based assays showed that FVIII(a) directly bound to TF with high affinity (Kd; ∼3 nM). (4) The effect of FVIIa/TF on in-Xase was evaluated in FXa generation assay. 0.1 nM FVIIa/TF, 1 nM FVIII, 90 nM FIX and 20 μM PL were reacted with 150 nM FX at various combinations. FVIIa/TF and FVIIa/TF/FVIII/FIX generated FXa with 3.9 and 10.4 nM/min, respectively. When FVIIa-inhibitor was added prior to addition of FX, FXa generated by FVIIa/TF and FVIIa/TF/FVIII/FIX were 5% and 46% (0.2 and 4.8 nM/min) of those without FVIIa-inhibitor, respectively. The latter was considered as FXa generated by in-Xase. Therefore, FXa derived from in-Xase was ∼40% of total FXa in this condition. (5) FVIIIa/FIXa (1 nM/2 nM)-dependent FXa generation in the presence of TF was evaluated. FXa generation in the presence of TF (0.02 and 0.3 nM) increased by ∼2 and ∼6-folds, respectively, of that in its absence. Furthermore, the functional affinity of FVIIIa for in-Xase complex in the presence of TF (0.1 nM), showed an ∼1.5-fold greater than that in its absence (Km; 4.9 ± 0.4 and 7.1 ± 0.9 nM, respectively). In conclusion, FVIIa/TF can generate FVIIIa in early timed-phase in vitro as well as FXa and FIXa, and possess potential of forming in-Xase. In addition, TF directly binds to FVIII(a), and functions in-Xase complex more efficiently by enhancing the affinity of FVIIIa for in-Xase. Although TF-dependent these reactions may be terminated rapidly via anticoagulant systems such as tissue factor pathway inhibitor, our data suggest that interactions of FVIII with TF might contribute to the acceleration of FXa generation in the initiation phase of blood coagulation. Disclosures Okuda: Sysmex Corporation: Employment.

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