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Canine haemangiosarcoma (HSA) is a highly aggressive cancer often associated with coagulation abnormalities. Statins, inhibitors of 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase (HMGCR) clinically prescribed for hypercholesterolemia, are also believed to possess antitumour and anticoagulant properties by inhibiting downstream Akt activation. Akt phosphorylation is involved in the mechanism of the antitumour and tissue factor (TF)‐lowering effects of statins. In the present study, we aimed to investigate whether statins could inhibit cell viability while concurrently inducing anticoagulant properties by regulating the expression of TFs in canine HSA cells. Using reverse transcription‐quantitative polymerase chain reaction (RT‐qPCR), we initially exclusively detected HMGCR mRNA expression in canine HSA tissues and cell lines but not in normal cephalic vein and spleen tissues. Moreover, treatment with lipophilic statins, including atorvastatin, fluvastatin, and simvastatin, inhibited cell viability in a concentration‐dependent manner and decreased TF expression both at the mRNA and protein levels, as evidenced by cell viability assays, RT‐qPCR, and immunoblotting, respectively. Further investigation using cell viability assays and flow cytometry revealed that simvastatin decreased Akt phosphorylation, and MK‐2206, a specific Akt inhibitor, mirrored the effect of simvastatin on cell viability and cell cycle arrest. However, MK‐2206 exhibited different effects on TF expression depending on the cell type, indicating that Akt phosphorylation may not consistently regulate TF expression. Overall, this study provides insights into the potential therapeutic use of statins in targeting tumour growth and coagulation abnormalities in canine HSA. Further research is warranted to fully elucidate the underlying mechanisms and clinical applications of statins in canine HSA treatment. [ABSTRACT FROM AUTHOR]

ABSTRACT Background and Aims Methods Results Conclusions Tissue factor‐expressing microvesicles (MV‐TF) have been found to correlate with thrombotic complications in various diseases. Simultaneously, there is expanding research regarding the effect of the coagulation cascade on liver fibrosis progression. The aim of our manuscript was to evaluate MV‐TF activity in patients with cirrhosis and its correlation with disease severity.We prospectively enrolled 82 patients [11 with cirrhosis and hepatocellular cancer (Group 1), 50 with cirrhosis (Group 2) and 21 controls (Group 3)]. Extensive workup for disease staging and exclusion criteria was undertaken. Exclusion criteria included thrombophilia, history of thrombosis, recent hospitalisation, ongoing infection, alcohol dependence, cancer, haematological diseases and use of anticoagulant, antiplatelet or contraceptive drugs. Plasma tissue factor antigen concentration and MV‐TF activity were assessed.MV‐TF showed median values of 4.03 [1.57], 3.17 [1.59] and 2.26 [1.23] pg/mL in Groups 1, 2 and 3, respectively. There was a statistically significant difference between Groups 1 and 3 (p < 0.001) and Groups 2 and 3 (p = 0.003), while Group 1 had higher values than Group 2 without statistical significance (p = 0.088). In Group 2, the patients' Child‐Pugh (CP) stage was A in 56%, B in 26% and C in 18% of cases. MV‐TF activity significantly correlated with decompensated cirrhosis (p = 0.005) and higher CP stage (p = 0.011). Finally, MV‐TF activity significantly correlated with 12‐month mortality (p = 0.021).MV‐TF activity is elevated in patients with cirrhosis, showing a significant correlation with disease severity. MV‐TF may play a role in the procoagulant imbalance of liver cirrhosis and their contribution in disease progression should be studied further. [ABSTRACT FROM AUTHOR]

Introduction: Patients with coronary artery disease (CAD) display a prothrombotic fibrin clot phenotype, involving low permeability and resistance to lysis. The determinants of this phenotype remain elusive. Circulating tissue factor (TF) and activated factor XI (FXIa) are linked to arterial thromboembolism. We investigated whether detectable active TF and FXIa influence fibrin clot properties in CAD. Methods: In 118 CAD patients (median age 65 years, 78% men), we assessed Ks, an indicator of clot permeability, and clot lysis time (CLT) in plasma‐based assays, along with the presence of active TF and FXIa. We also analysed proteins involved in clotting and thrombolysis, including fibrinogen, plasminogen activator inhibitor‐1 (PAI‐1) and thrombin activatable thrombolysis inhibitor (TAFI). During a median 106 month (interquartile range 95–119) follow‐up, myocardial infarction (MI), stroke, systemic thromboembolism (SE) and cardiovascular (CV) death were recorded. Results: Circulating TF and FXIa, detected in 20.3% and 39.8% of patients, respectively, were associated with low Ks and prolonged CLT. Solely FXIa remained an independent predictor of low Ks and high CLT on multivariable analysis. Additionally, fibrinogen and PAI‐1 were associated with low Ks, while PAI‐1 and TAFI—with prolonged CLT. During follow‐up low Ks and prolonged CLT increased the risk of MI and the latter also a composite endpoint of MI, stroke/SE or CV death. Conclusions: To our knowledge, this study is the first to show that circulating FXIa is associated with prothrombotic fibrin clot properties in CAD, suggesting additional mechanisms through which FXIa inhibitors could act as novel antithrombotic agents in CAD. [ABSTRACT FROM AUTHOR]

Aim: Tissue factor (TF), the primary initiator of the extrinsic coagulation pathway, contributes to the generation of a hypercoagulable and prothrombotic state in cancer patients. TF pathway inhibitor (TFPI) is a major inhibitor of TF‐mediated coagulation pathway. The two proteins, TFPI1 and TFPI2, are encoded by separate genes. Indeed, various cancer patients with venous thromboembolism (VTE) had significantly lower TFPI1 levels than those without VTE. In contrast, serum TFPI2 level was found to increase in ovarian cancer patients with VTE. It remains unclear why TFPI2, unlike TFPI1, is elevated in ovarian cancer patients with VTE. The aim of this review is to explore the pathophysiological role of TFPI2 on the coagulation and fibrinolysis system. Methods: A literature search was performed from inception to April 30, 2022 in the PubMed and Google Scholar databases. Results: TFPI1 and TFPI2 are homologs with different protease inhibitory activities in the coagulation and fibrinolysis system. TFPI1 inhibits TF/factor VIIa (FVIIa) catalyzed factor X (FX) activation. On the other hand, TFPI2 is unlikely to affect TF‐initiated thrombin generation, but it has strong inhibitory activity against plasmin. Plasmin is involved in fibrin degradation, clot lysis, and inactivation of several coagulation factors (such as FV, FVIII, FIX, and FX). TFPI2 may increase the risk of VTE by inhibiting plasmin‐dependent fibrinolysis. Conclusion: TFPI1 and TFPI2 may have different key functions in regulating the coagulation and fibrinolytic systems. [ABSTRACT FROM AUTHOR]

Background: Vascular diseases are highly associated with inflammation and thrombosis. Elucidating links between these two processes may provide a clearer understanding of these diseases, allowing for the design of more effective treatments. The activation of complement component 1 (C1) is a crucial contributor to innate immunity and is associated with significant concentrations of circulating C1q. Many pathological pathways initiate when C1q interacts with gC1qR. This interaction plays a major role in inflammation observed during atherosclerosis and the initiation of intrinsic coagulation. However, the effects of C1 and the role of C1q/gC1qR on extrinsic coagulation, which is the more physiologically relevant coagulation arm, has not been studied. We hypothesized that C1q binding to gC1qR enhances the expression of tissue factor (TF) in adventitial fibroblasts and vascular smooth muscle cells, the primary TF bearing cells in the body. Methods: Using an enzyme‐linked immunosorbent assay approach, TF expression and the role of gC1qR was observed. Cells were conditioned for 1 h with C1q or a gC1qR blocker and C1q, to assess the role of gC1qR. Additionally, cell growth characteristics were monitored to assess changes in viability and metabolic activity. Results: Our results indicate that the expression of TF increased significantly after incubation with C1q as compared with unconditioned cells. Cells conditioned with gC1qR blockers and C1q exhibited no change in TF expression when compared with cells conditioned with the blocking antibodies alone. Our results show no significant differences in metabolic activity or cell viability under these conditions. Conclusions: This indicates that gC1qR association with C1q induces TF expression and may initiate extrinsic coagulation. Overall, this data illustrates a role for C1q in the activation of extrinsic coagulation and that gC1qR activity may link inflammation and thrombosis.Vascular diseases are associated with altered inflammation and thrombosis. We have identified a link between complement activity and activation of extrinsic coagulation. [ABSTRACT FROM AUTHOR]

Tissue factor (TF) is a procoagulant protein released from activated host cells, such as monocytes, and tumor cells on extracellular vesicles (EVs). TF + EVs are observed in the circulation of patients with various types of diseases. In this review, we will summarize the association between TF + EVs and activation of coagulation and survival in different types of diseases, including cancer, sepsis, and infections with different viruses, such as human immunodeficiency virus (HIV), influenza A virus (IAV), and severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). We will also discuss the source of TF + EVs in various diseases. EVTF activity is associated with thrombosis in pancreatic cancer patients and coronavirus disease 2019 patients (COVID‐19) and with disseminated intravascular coagulation in cancer patients. EVTF activity is also associated with worse survival in patients with cancer and COVID‐19. Monocytes are the major sources of TF + EVs in sepsis, and viral infections, such as HIV, Ebola virus, and SARS‐CoV‐2. In contrast, alveolar epithelial cells are the major source of TF + EVs in bronchoalveolar lavage fluid in COVID‐19 and influenza A patients. These studies indicate that EVTF activity could be used as a biomarker to identify patients that have an increased risk of coagulopathy and mortality. [ABSTRACT FROM AUTHOR]

Activation of the coagulation cascade is a critical, evolutionarily conserved mechanism that maintains hemostasis by rapidly forming blood clots in response to blood‐borne infections and damaged blood vessels. Coagulation is a key component of innate immunity since it prevents bacterial dissemination and can provoke inflammation. The term immunothrombosis describes the process by which the innate immune response drives aberrant coagulation, which can result in a lethal condition termed disseminated intravascular coagulation, often seen in sepsis. In this review, we describe the recently uncovered molecular mechanisms underlying inflammasome‐ and STING‐driven immunothrombosis induced by bacterial and viral infections, culminating in tissue factor (TF) activation and release. Current anticoagulant therapeutics, while effective, are associated with a life‐threatening bleeding risk, requiring the urgent development of new treatments. Targeting immunothrombosis may provide a safer option. Thus, we highlight preclinical tools which target TF and/or block canonical (NLRP3) or noncanonical (caspase‐11) inflammasome activation as well as STING‐driven TF release and discuss clinically approved drugs which block key immunothrombotic processes and, therefore, may be redeployed as safer anticoagulants. [ABSTRACT FROM AUTHOR]

Background: Convallotoxin (CNT), present in lily of the valley (Convallaria majalis), is a toxin that causes food poisoning among humans and companion animals. Although various symptoms of CNT poisoning have been well described, hypercoagulability owing to CNT is only empirically known among some veterinarians, and the underlying mechanism remains to be elucidated. CNT exerts cytotoxic effects on endothelial cells. Objectives: This study aimed to determine whether CNT induces the expression of tissue factor (TF), a potent initiator of the extrinsic coagulation cascade, in endothelial cells and leads to a hypercoagulable state. Methods: Human umbilical vein endothelial cells (HUVECs) were used for in vitro experiments. HUVECs were treated with or without CNT (50 and 100 nM) for 4 h. Phosphate‐buffered saline was used as a control. Cell viability was determined using the WST‐8 assay. Quantitative real‐time polymerase chain reaction was performed to determine TF mRNA expression. TF protein expression was observed using a laser scanning confocal microscope. Results: The viability of HUVECs significantly reduced after CNT treatment compared with that of non‐treated cells (p < 0.05). Moreover, a significant increase in TF mRNA and protein expression was observed after 4 h of CNT treatment. CNT elicited these effects in a dose‐dependent manner. Conclusions: TF expression induced by CNT in endothelial cells can contribute to the development of a hypercoagulable state. The present study partially revealed the mechanisms underlying the CNT‐induced hypercoagulable state. The findings can contribute to the development of a novel therapy for lily of the valley poisoning. [ABSTRACT FROM AUTHOR]

Pancreatic cancer frequently involves cancer-associated thromboembolism, which is strongly associated with poor prognosis. Tissue factor, a blood coagulation factor largely produced in cancer patients as a component of extracellular vesicles, plays a key role in the incidence of cancer-associated thromboembolism in patients with pancreatic cancer. However, no prospective studies have been published on the relationship between tissue factor and cancer-associated thromboembolism or patient clinical characteristics, including recent chemotherapy regimens. Thus, we aimed to address this in a Japanese cohort of 197 patients and 41 healthy volunteers. Plasma tissue factor levels were measured by ELISAs preevaluated by tissue factor specificity. Multivariable analysis was used to identify independent predictors of cancer-associated thromboembolism. We found that the cancer-associated thromboembolism rate in the patient cohort was 6.6% (4.6%, venous thromboembolism; 2.0%, arterial thromboembolism). Tissue factor levels of 100 pg/mL or higher at patient registration were predictive of cancer-associated thromboembolism, with positive and negative predictive values of 23.1% and 94.6%, respectively. Multivariable analysis showed that plasma tissue factor levels were an independent predictive factor for cancer-associated thromboembolism, with a risk ratio of 5.54 (95% confidence interval, 1.02-30.09). Unlike in healthy volunteers and patients without cancer-associated thromboembolism, tissue factor levels were highly correlated with extracellular vesicles' procoagulant activity in patients developing cancer-associated thromboembolism. Taken together, our data show that the tissue factor levels at patient registration were a predictive factor for cancer-associated thromboembolism in this cohort of patients with pancreatic cancer. [ABSTRACT FROM AUTHOR]

As pump thrombosis is reduced in current‐generation ventricular assist devices (VAD), adverse events such as bleeding or stroke remain at unacceptable rates. Thrombosis around the VAD inlet cannula (IC) has been highlighted as a possible source of stroke events. Recent computational fluid dynamics (CFD) studies have attempted to characterize the thrombosis risk of different IC‐ventricle configurations. However, purely CFD simulations relate thrombosis risk to ad hoc criteria based on flow characteristics, with little consideration of biochemical factors. This study investigates the genesis of IC thrombosis including two elements of the Virchow's triad: endothelial injury and hypercoagulability. To this end a multi‐scale thrombosis simulation that includes platelet activity and coagulation reactions was performed. Our results show significant thrombin formation in stagnation regions (|u| < 0.005 m/s) close to the IC wall. In addition, high shear‐mediated platelet activation was observed over the leading‐edge tip of the cannula. The current study reveals the importance of biochemical factors to the genesis of thrombosis at the ventricular‐cannula junction in a perioperative state. This study is a first step toward the long‐term objective of including clinically relevant pharmacological kinetics such as heparin or aspirin in simulations of inflow cannula thrombosis. [ABSTRACT FROM AUTHOR]

Background: Severe carotid stenosis is a common cause of stroke. In addition, previous clinical studies revealed that patients symptomatic of carotid stenosis suffer from increased episodes of stroke compared with their asymptomatic counterparts. However, the mechanism underlying these differences in the recurrence of stroke remains unclear. Objective: The present study aimed to evaluate the levels of neutrophil extracellular traps (NETs) in the plasma of patients with severe carotid stenosis and investigate whether NETs induced procoagulant activity (PCA) in severe carotid stenosis. The study also sought to investigate the interactions between platelets or endothelial cells (ECs) and NETs. Methods: The levels of NETs in plasma were quantified using enzyme‐linked immunosorbent assay (ELISA). In addition, NETting neutrophils and neutrophil‐platelet aggregates were detected through flow cytometry. On the other hand, the morphology of NETs formation and endothelial cells were analyzed through confocal microscopy. Finally, the procoagulant activity (PCA) of NETs and endothelial cells were assessed through ELISA and fibrin formation. Results: Patients with symptomatic carotid stenosis patients had significantly higher levels of NETs markers compared with their asymptomatic counterparts and healthy subjects. In addition, increased levels of neutrophil‐platelet aggregates induced the generation of NETs in patients with symptomatic carotid stenosis. Moreover, NETs contributed to PCA through tissue factor (TF), in patients with carotid stenosis. Furthermore, NETs disrupted the endothelial barrier and converted endothelial cells (ECs) into PCA to enhance the PCA in patients with carotid stenosis. Conclusions: The current study revealed differences in the levels of NETs in the plasma of symptomatic and asymptomatic patients suffering from carotid stenosis. The study also uncovered the interaction between NETs and thrombogenicity in carotid stenosis. Therefore, inhibiting NETs may be a potential biomarker and therapeutic target for recurring stroke in severe carotid stenosis. [ABSTRACT FROM AUTHOR]

Uncontrolled hemorrhage accounts for a significant proportion of annual mortality worldwide. The development of bioinspired hemostatic composites can effectively reduce hemorrhage and related deaths. This work aims to develop an efficient hemostatic agent by incorporating tissue factor (TF) integrated liposomes and collagen, which are capable of augmenting different inherent hemostatic mechanisms, into hemostasis‐stimulating alginate matrix. The composite of TF, collagen and alginate (TCA) was made into hydrogel beads with a diameter range of 2.5–3.5 mm, followed by electron microscopy, infrared spectroscopy, rheological, and swelling characterization to confirm its composition and hydrogel nature. When the TCA beads were introduced into simulated body fluid, a controlled release of the loaded TF‐liposomes was observed, which also accelerated with the increase of temperature, obtaining intact free proteoliposomes as demonstrated by fluorescence measurement. It is further seen that TCA beads induced the coagulation of whole rabbit blood in about 4.5 min, as compared to ~14.4 min for the control with only recalcified blood. The lipidated TF, collagen and alginate in TCA beads showed a positive synergistic effect on coagulation, while among them a decreasing procoagulant effect was observed. Finally, we demonstrated by a live/dead cell assay that TCA particles had undetectable cytotoxicity. Thus, the TCA hydrogel macrobeads may offer a potential platform for the development of potent hemostatic agents. [ABSTRACT FROM AUTHOR]

Tissue factor (TF), the trigger protein of the extrinsic blood coagulation cascade, is abundantly expressed in various cancers including gastric cancer. Anti‐TF monoclonal antibodies (mAbs) capable of targeting cancers have been successfully applied to armed antibodies such as antibody‐drug conjugates (ADCs) and molecular imaging probes. We prepared an anti‐TF mAb, clone 1084, labeled with astatine‐211 (211At), as a promising alpha emitter for cancer treatment. Alpha particles are characterized by high linear energy transfer and a range of 50‐100 µm in tissue. Therefore, selective and efficient tumor accumulation of alpha emitters results in potent antitumor activities against cancer cells with minor effects on normal cells adjacent to the tumor. Although the 211At‐conjugated clone 1084 (211At‐anti‐TF mAb) was disrupted by an 211At‐induced radiochemical reaction, we demonstrated that astatinated anti‐TF mAbs eluted in 0.6% or 1.2% sodium ascorbate (SA) solution were protected from antibody denaturation, which contributed to the maintenance of cellular binding activities and cytocidal effects of this immunoconjugate. Although body weight loss was observed in mice administered a 1.2% SA solution, the loss was transient and the radioprotectant seemed to be tolerable in vivo. In a high TF–expressing gastric cancer xenograft model, 211At‐anti‐TF mAb in 1.2% SA exerted a significantly greater antitumor effect than nonprotected 211At‐anti‐TF mAb. Moreover, the antitumor activities of the protected immunoconjugate in gastric cancer xenograft models were dependent on the level of TF in cancer cells. These findings suggest the clinical availability of the radioprotectant and applicability of clone 1084 to 211At‐radioimmunotherapy. [ABSTRACT FROM AUTHOR]

Ovarian cancer is a known risk factor of venous thromboembolism (VTE). Thrombogenic factor expression and lymphocytic infiltrate have been reported in endometriosis and ovarian cancers. We reviewed 30 cases of ovarian carcinomas (high grade serous carcinoma, 10; endometrioid carcinoma, 10; clear cell carcinoma (CCC), 10) and 16 endometriotic lesions. We immunohistochemically investigated the expressions of tissue factor (TF), podoplanin, P‐selectin, and number of CD4 and CD8 positive lymphocytes in cancer tissue and endometriotic lesions, along with their relationship with VTE. The expression of TF was higher in CCC. The TF expression and the number of CD8 positive cells were higher in cancer tissues with VTE than in those without VTE. The podoplanin or P‐selectin expression did not differ among histological types or between cases with and without VTE. Our results demonstrated a high TF expression and intraepithelial CD8 cells in CCC, which were associated with VTE. The results suggest that infiltrating lymphocytes may affect TF expression that, in turn, influences VTE. [ABSTRACT FROM AUTHOR]

The pathogenesis of chronic spontaneous urticaria (CSU), also called chronic idiopathic urticaria, has been considered to be associated with the activation of the extrinsic blood coagulation cascade. However, the trigger for the extrinsic coagulation cascade in patients with CSU remains unclear. We previously reported that histamine and lipopolysaccharide (LPS) synergistically induced the expression of tissue factor (TF), a trigger for the extrinsic coagulation cascade, in human umbilical vein endothelial cells (HUVEC). Because the elevation of tumor necrosis factor (TNF)‐α, interleukin (IL)‐33, IL‐1β and vascular endothelial growth factor (VEGF) in serum has also been observed in patients with CSU, we examined the effects of LPS, TNF‐α, IL‐33, IL‐1β, VEGF and histamine on TF expression in HUVEC by reverse transcription polymerase chain reaction and flow cytometry, as well as examining the activity that triggers the extrinsic coagulation cascade and induces intercellular gap formation of HUVEC in the presence of plasma by Actochrome® TF activity assay and impedance sensor, respectively. The expression of TF mRNA and surface protein of TF on HUVEC in response to histamine or VEGF were synergistically enhanced by the treatment with LPS, TNF‐α, IL‐33 or IL‐1β. Moreover, the activation of the extrinsic coagulation pathway and intercellular gap formation of HUVEC in response to histamine or VEGF were also synergistically increased in the presence of TNF‐α and LPS. Thus, TF expression on vascular endothelial cells was strongly enhanced by co‐stimulation with CSU‐related molecules in blood. Blocking a common pathway of LPS, TNF‐α, IL‐33 and IL‐1β, and/or that of VEGF and histamine may be an effective therapeutic measure for patients with severe and refractory CSU. [ABSTRACT FROM AUTHOR]

Acute lung injury (ALI) caused by gas explosion is common, and warrants research on the underlying mechanisms. Specifically, the role of abnormalities of coagulation and fibrinolysis in this process has not been defined. It was hypothesized that the abnormal coagulation and fibrinolysis promoted ALI caused by gas explosion. Based on the presence of ALI, 74 cases of gas explosion injury were divided into the ALI and non‐ALI groups. The results of prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), and platelet count (PLT) were collected within 24 hours and compared between the groups. ALI models caused by gas explosion were established in Sprague Dawley rats, and injuries were evaluated using hematoxylin and eosin (HE) staining and histopathological scoring. Moreover, the bronchoalveolar lavage fluid (BALF) was collected to examine thrombin‐antithrombin complex (TAT), tissue factor (TF), tissue factor pathway inhibitor (TFPI), and plasminogen activator inhibitor‐1 (PAI‐1) levels by enzyme‐linked immunosorbent assay (ELISA). The patients in ALI group had shorter PT and longer APTT, raised concentration of FIB and decreased number of PLT, as compared to the non‐ALI group. In ALI rats, the HE staining revealed red blood cells in alveoli and interstitial thickening within 2 hours which peaked at 72 hours. The levels of TAT/TF in the BALF increased continually until the seventh day, while the PAI‐1 was raised after 24 hours and 7 days. The TFPI was elevated after 2 hours and 24 hours, and then decreased after 72 hours. Abnormalities in coagulation and fibrinolysis in lung tissues play a role in ALI caused by gas explosion. [ABSTRACT FROM AUTHOR]

Anaplastic thyroid cancer (ATC) is the most aggressive subtype of thyroid cancers with a dismal prognosis. It is aimed to explore a new biomarker and devise a marker‐dependent theranostic pair for ATC. Flow cytometry is used to determine tissue factor (TF) expression in thyroid cancer cell lines. ALT‐836, a TF‐specific monoclonal antibody, is radiolabeled with 64Cu to develop 64Cu‐NOTA‐ALT‐836. The diagnostic utility is assessed by immuno‐positron emission tomography (immunoPET) imaging in ATC models. To facilitate total surgical removal of orthotopic ATCs, a near‐infrared fluorescent imaging probe IRDye 800CW‐ALT‐836 is designed. As the therapeutic component, 131I‐ALT‐836 is further developed and the radioimmunotherapy (RIT) efficacy of this agent is interrogated in orthotopic ATC models. The results demonstrate that TF is highly expressed on the ATC cell line THJ‐16T. 64Cu‐NOTA‐ALT‐836 immunoPET imaging clearly delineates both subcutaneous and orthotopic ATCs, with a peak tumor uptake of 19.93 ± 2.17% ID per g (n = 3) and 37.20 ± 1.71% ID per g (n = 3), respectively. Fluorescent imaging with IRDye 800CW‐ALT‐836 facilitates the total resection of orthotopic ATCs. Moreover, 131I‐ALT‐836 RIT prolongs the survival of ATC‐bearing mice. Taken together, TF is a promising marker for ATC and successive use of 64Cu‐NOTA‐ALT‐836 and 131I‐ALT‐836 can realize precise management of ATC. [ABSTRACT FROM AUTHOR]

The mechanisms underlying coagulation abnormalities in sepsis and septic acute lung injury remain unclear. Tissue factor (TF) initiates coagulation; its production can be regulated by reactive oxygen species (ROS); and monocytes/macrophages produce pathological TF during sepsis. The SUMO2/3 protease SENP3 is redox‐sensitive, and SENP3 accumulation in lipopolysaccharide (LPS)‐activated macrophages is ROS‐dependent. To explore whether SENP3 contributes to LPS‐activated coagulation, we used mice with Senp3 conditional knockout (cKO) in myeloid cells. In the model of LPS‐induced sepsis, SENP3 cKO mice exhibited less severe acute lung injury than SENP3 fl/fl mice. SENP3 cKO mice exhibited decreased TF expression in monocytes and alveolar macrophages, with consequently compromised coagulation in their blood and lungs. In vitro results showed that ROS‐induced SENP3 accumulation contributed to LPS‐induced TF expression, which was reduced by JNK inhibitor SP600125. Furthermore, mice injected with LPS following SP600125 (75 mg/kg) treatment showed decreased monocytes/macrophages TF production and alleviated coagulation activation, with less severe lung injury and higher survival rates. Collectively, the results suggest that SENP3 mediates LPS‐induced coagulation activation by up‐regulating monocyte/macrophage TF production in a JNK‐dependent manner. This work provides new insights into ROS regulation of LPS‐activated coagulation and reveals a link between SUMOylation and coagulation. [ABSTRACT FROM AUTHOR]

Background: Tumor stroma, of which fibroblasts are the most abundant cell, resembles a non‐healing wound, where a procoagulant environment creates a permissive milieu for cancer growth. We aimed to determine if tumor expression of coagulation factors (procoagulant phenotype), and systemic hypercoagulability, occur at the preinvasive (ductal carcinoma in situ; DCIS) stage and correlate with breast cancer subtype, disease‐free survival (DFS), and overall survival (OS). Methods: In a prospective cohort of early breast cancer (DCIS, n = 76; invasive, n = 248) tumor, normal breast and plasma were examined. Fibroblast and epithelial expression of Tissue Factor (TF), thrombin, PAR1, PAR2, and plasma thrombin‐antithrombin (TAT) and D‐dimer were correlated with clinicopathological data, and 5‐year survival. Results: Fibroblast expression of TF, thrombin, and PAR1 was increased in DCIS and invasive cancer compared to normal breast fibroblasts (P ≤.003, all). Fibroblast TF, thrombin, PAR1, and PAR2 was increased in cancers with high Ki67, high grade, ER‐ (vs ER+), and HER2+ (vs HER2‐) (all P <.05). On univariate analysis, fibroblast TF expression was inversely associated with DFS (P =.04) and OS (P =.02). D‐dimer was higher in node positive (507 (CI: 411‐625) ng/mL, n = 68) vs negative patients (428 (CI: 387‐472) ng/mL, n = 171, P =.004) and inversely associated with OS (P =.047). On multivariate analysis, plasma TAT was associated with reduced OS (HR 3.26, CI 1.16‐3.1, P =.02), with a high plasma TAT (≥3.2 ng/mL) associated with > 3‐fold mortality risk compared to low TAT. Conclusion: This demonstrates procoagulant phenotypic changes occur in fibroblasts at the preinvasive stage. Fibroblast procoagulant phenotype is associated with aggressive breast cancer subtypes and reduced survival. Coagulation may be a therapeutic target in breast cancer. [ABSTRACT FROM AUTHOR]

Protease‐activated receptors (PARs) are a unique class of G‐protein‐coupled transmembrane receptors, which revolutionized the perception of proteases from degradative enzymes to context‐specific signaling factors. Although PARs are traditionally known to affect several vascular responses, recent investigations have started to pinpoint the functional role of PAR signaling in the gastrointestinal (GI) tract. This organ is exposed to the highest number of proteases, either from the gut lumen or from the mucosa. Luminal proteases include the host's digestive enzymes and the proteases released by the commensal microbiota, while mucosal proteases entail extravascular clotting factors and the enzymes released from resident and infiltrating immune cells. Active proteases and, in case of a disrupted gut barrier, even entire microorganisms are capable to translocate the intestinal epithelium, particularly under inflammatory conditions. Especially PAR‐1 and PAR‐2, expressed throughout the GI tract, impact gut permeability regulation, a major factor affecting intestinal physiology and metabolic inflammation. In addition, PARs are critically involved in the onset of inflammatory bowel diseases, irritable bowel syndrome, and tumor progression. Due to the number of proteases involved and the multiple cell types affected, selective regulation of intestinal PARs represents an interesting therapeutic strategy. The analysis of tissue/cell‐specific knockout animal models will be of crucial importance to unravel the intrinsic complexity of this signaling network. Here, we provide an overview on the implication of PARs in intestinal permeability regulation under physiologic and disease conditions. [ABSTRACT FROM AUTHOR]

Tissue factor (TF) is known to be overexpressed in various cancers including pancreatic cancer. The upregulation of TF expression has been observed not only in tumor cells, but also in tumor stromal cells. Because of the potential of TF as a delivery target, several studies investigated the effectiveness of Ab‐drug conjugates (ADCs) against TF for cancer therapy. However, it is still unclear whether anti‐TF ADC can exert toxicity against both tumor cells and tumor stromal cells. Here, we prepared ADC using a rat anti‐mouse TF mAb (clone.1157) and 2 types of in vivo murine pancreatic cancer models, one s.c. and other orthotopic with an abundant tumor stroma. We also compared the feasibility of bis‐alkylating conjugation (bisAlk) with that of conventional maleimide‐based conjugation (MC). In the s.c. models, anti‐TF ADC showed greater antitumor effects than control ADC. The results also indicated that the bisAlk linker might be more suitable than the MC linker for cancer treatments. In the orthotopic model, anti‐TF ADC showed greater in vivo efficacy and more extended survival time control ADC. Treatment with anti‐TF ADC (20 mg/kg, three times a week) did not affect mouse body weight changes in any in vivo experiment. Furthermore, immunofluorescence staining indicated that anti‐TF ADC delivered agents not only to TF‐positive tumor cells, but also to TF‐positive tumor vascular endothelial cells and other tumor stromal cells. We conclude that anti‐TF ADC should be a selective and potent drug for pancreatic cancer therapy. [ABSTRACT FROM AUTHOR]

Although direct adhesion of cancer cells to the mesothelial cell layer is considered to be a key step for peritoneal invasion of ovarian cancer cell masses (OCM), we recently identified a different strategy for the peritoneal invasion of OCM. In 6 out of 20 cases of ovarian carcinoma, extraperitoneal growth of the OCM was observed along with the neovascularization of feeding vessels, which connect the intraperitoneal host stroma and extraperitoneal lesions through the intact mesothelial cell layer. As an early step, the OCMs anchor in the extraperitoneal fibrin networks and then induce the migration of CD34‐positive and vascular endothelial growth factor A (VEGF‐A)‐positive endothelial cells, constructing extraperitoneal vascular networks around the OCM. During the extraperitoneal growth of OCM, podoplanin‐positive and α smooth muscle actin (αSMA)‐positive cancer‐associated fibroblasts (CAF) appears. In more advanced lesions, the boundary line of mesothelial cells disappears around the insertion areas of feeding vessels and then extraperitoneal and intraperitoneal stroma are integrated, enabling the OCM to invade the host stroma, being associated with CAF. In addition, tissue factors (TF) are strongly detected around these peritoneal implantation sites and their levels in ascites were higher than that in blood. These findings demonstrate the presence of neovascularization around fibrin net‐anchored OCMs on the outer side of the intact peritoneal surface, suggesting a novel strategy for peritoneal invasion of ovarian cancer and TF‐targeted intraperitoneal anti‐cancer treatment. We observed and propose a novel strategy for peritoneal implantation of ovarian cancer. The strategy includes the preinvasive growth of fibrin‐anchored cancer cells along with neovascularization on the outer side of the intact peritoneal surface. [ABSTRACT FROM AUTHOR]

Summary: Background: Equine herpesvirus type 1 (EHV‐1) is the cause of respiratory disease, abortion storms, and outbreaks of herpesvirus myeloencephalopathy (EHM). Infection of the spinal cord is characterised by multifocal regions of virally infected vascular endothelium, associated with vasculitis, thrombosis and haemorrhage that result in ischaemia and organ dysfunction. However, the mechanism of thrombosis in affected horses is unknown. Objectives: To evaluate tissue factor (TF) procoagulant activity and thrombin–antithrombin complex (TAT) levels in horses following infection with EHV‐1. Study design: In vitro and in vivo studies following experimental EHV‐1 infection. Methods: Horses were infected with EHV‐1 and levels of peripheral blood mononuclear cell (PBMC)‐associated TF activity; plasma and cerebrospinal fluid (CSF)‐derived microvesicle (MV)‐associated TF activity and TAT complexes in plasma were examined. Results: EHV‐1 infection increased PBMC TF procoagulant activity in vitro and in vivo. In infected horses, this increase was observed during the acute infection and was most marked at the onset and end of viraemia. However, no significant differences were observed between the horses that showed signs of EHM and the horses that did not develop EHM. Significant changes in MV‐associated TF procoagulant activity and TAT complexes were not observed in infected horses. Main limitations: A small number of horses typically exhibit clinical EHM following experimental infection. Conclusions: The results indicate that EHV‐1 infection increases PBMC‐associated TF procoagulant activity in vivo and in vitro. Additional in vivo studies are needed to better understand the role of TF‐dependent coagulation during EHM pathogenesis in horses. [ABSTRACT FROM AUTHOR]

Abstract: Although cancer is associated with coagulation disorders, it is still unclear how the combination of tumor cell and host factors enhance the hypercoagulable state of cancer patients. Emerging evidence points to a central role for tumor endosomal and plasma membrane‐derived vesicular components in the pathogenesis of cancer‐related thrombosis. In particular, tumor cell membranes and extracellular vesicles (EV) harbor lipids and proteinaceous coagulation factors able to initiate multiple points within the coagulation matrix. The impact of chemotherapy upon a host already burdened with a hypercoagulable state increases the risk of pathological coagulation. We argue that chemotherapy‐induced EV harbor the most active components for cancer related thrombosis and discuss how membrane components of the host and tumor act to initiate coagulation to enhance thrombotic risk in cancer patients. [ABSTRACT FROM AUTHOR]

Abstract: Background: To examine the expression of D‐dimer, fibrinogen (FIB), leukocyte, C‐reactive protein (CRP) and tissue factor (TF) released from monocyte in non‐small cell lung cancer (NSCLC) patients with or without venous thromboembolism (VTE) and analyse the correlation, to explore the possible mechanisms. Methods: Seventy‐two patients confirmed the diagnosis of lung cancer, among whom 10 with VTE were enrolled into the study from November 2012 to January 2014 in the First Affiliated Hospital of Fujian Medical University and 30 healthy subjects were also enrolled as the control group. Ficoll and Percoll density gradient centrifugation separated of peripheral blood monocyte. Monocyte TF mRNA expression was detected using reverse transcriptase‐polymerase chain reaction (RT‐PCR). Results: There were significant differences in different stages of the cancer (P < .05) and no significance among the histopathologic types (P > .05) for the expression of monocyte TF mRNA in NSCLC patients, its expression was significantly higher in cancer with lymph node metastasis than those without lymph node metastasis (P < .01). Meanwhile, in NSCLC patients with VTE, the expression of monocyte TF mRNA was significantly higher than that in patients without VTE (P < .01). Difference of the survival curves between the low monocyte TF mRNA expression and the high monocyte TF mRNA expression was significant (Log‐rank x2 = 4.923, P < .05). Conclusions: Monocyte TF may be a relevant source of TF‐mediated thrombogenicity in NSCLC patients and may be associated with prognosis in NSCLC. [ABSTRACT FROM AUTHOR]

publisher‐imprint‐name Springer volume‐issue‐count 1 issue‐article‐count 0 issue‐toc‐levels 0 issue‐pricelist‐year 2017 issue‐copyright‐holder The Author(s) issue‐copyright‐year 2017 article‐contains‐esm No article‐numbering‐style Unnumbered article‐registration‐date‐year 2017 article‐registration‐date‐month 8 article‐registration‐date‐day 16 article‐toc‐levels 0 toc‐levels 0 volume‐type Regular journal‐product ArchiveJournal numbering‐style Unnumbered article‐grants‐type OpenChoice metadata‐grant OpenAccess abstract‐grant OpenAccess bodypdf‐grant OpenAccess bodyhtml‐grant OpenAccess bibliography‐grant OpenAccess esm‐grant OpenAccess online‐first false pdf‐file‐reference BodyRef/PDF/40169_2017_Article_165.pdf target‐type OnlinePDF issue‐type Regular article‐type ReviewPaper journal‐subject‐primary Medicine & Public Health journal‐subject‐secondary Medicine/Public Health, general journal‐subject‐collection SC11 open‐access true --> Extracellular vesicles (EV) are blebs of cellular membranes, which entrap small portions of subjacent cytosol. They are released from a variety of cells, circulate in the blood for an unknown length of time and come to rest on endothelial surfaces. They contribute to an array of physiologic pathways, the complexity of which is still being investigated. They contribute to metastatic malignant cell implants and tumor‐related angiogenesis, possibly abetted by the tissue factor that they carry. It is thought that the adherence of the EV to endothelium is dependent upon a combination of their P‐selectin glycoprotein ligand‐1 and exposed phosphatidylserine, the latter of which is normally hidden on the inner bilayer of the intact cellular membrane. This manuscript reviews what is known about EV origins, their clearance from the circulation and how they contribute to malignant cell implants upon endothelium surfaces and subsequent tumor growth. [ABSTRACT FROM AUTHOR]

Introduction It has been recently suggested that microparticles ( MP) play a role in the pathogenesis of thrombotic complications. This study aimed to assess the contribution of procoagulant activity expressed by circulating MP in thrombotic events in MPN patients. Methods Seventy-four MPN patients were enrolled in a trans-sectional study. The MP procoagulant activity was measured using two assays: (i) the thrombin generation (TG) assay used in different conditions with the addition of both tissue factor (TF) and phospholipids (PL) and with the addition of TF or PL alone and (ii) the PROCOAG- PPL assay. Results The mean age was 62 (26 men and 48 women). The prevalence of thrombotic events was 28%. When comparing patients with thrombosis to those without, age, sex, MPN type, cardiovascular risk factors, and history of thrombosis were not significantly associated with thrombosis. The JAK2 V617F mutation was significantly associated with thrombotic events (90% vs 67%; P=.04). Results from the TG assay and the PROCOAG- PPL assays did not demonstrate a significant association between the MP procoagulant activity and thrombotic events. Conclusion The MP procoagulant activity did not predict thrombosis in MPN patients. The contribution of TG assay in the assessment of the thrombotic risk is still in debate. [ABSTRACT FROM AUTHOR]

Purpose This study aimed to evaluate the tissue factor (TF) concentration and activity in patients with oral lichen planus (OLP) under oxidative stress. Methods Twenty patients with OLP were selected from the patients who were referred for treatment to the Marmara University, Faculty of Dentistry, Oral and Maxillofacial Radiology Department. Twenty healthy subjects from faculty staff and their family members were selected for the study. Salivary TF concentration and TF activity; total oxidant capacity; total antioxidant capacity; total thiol, malondialdehyde and glutathione concentrations; and oxidative stress index were measured in saliva samples. Results Salivary total oxidant capacity, oxidative stress index and malondialdehyde and TF concentration and activity were significantly increased in the patient group compared to those in the control group. Total thiol and glutathione concentration and total antioxidant capacity were significantly decreased in the patient group. Conclusion Impaired oxidant-antioxidant balance and inflammatory features of OLP might cause an increase in the salivary TF concentration and activity. As TF factor plays a critical role in inflammation progress, the use of an antioxidant agent in OLP may decrease the salivary TF concentration by decreasing oxidative stress. The findings of this study might represent a novel approach to OLP monitoring and treatment in terms of TF as the measurement of TF is easy and cost-effective. [ABSTRACT FROM AUTHOR]

Background Neutrophils play a role in xenograft rejection. When neutrophils are stimulated, they eject the DNA-histone complex into the extracellular space, called neutrophil extracellular traps (NET). We investigated whether NET formation actively occurs in the xenograft and contributes to coagulation and endothelial activation. Methods Human whole blood was incubated with porcine aortic endothelial cells (pEC) from wild-type or α1,3-galactosyltransferase gene-knockout (GTKO) pigs. In the supernatant plasma from human blood, the level of the DNA-histone complex was measured by ELISA, and thrombin generation was measured using a calibrated automated thrombogram. Histone-induced tissue factor and adhesion molecule expression were measured by flow cytometry. Results pEC from both wild-type and GTKO pigs significantly induced DNA-histone complex formation in human whole blood. The DNA-histone complex produced shortened the thrombin generation time and clotting time. Histone alone dose-dependently induced tissue factor and adhesion molecule expression in pEC. Aurintricarboxylic acid pretreatment partially inhibited pEC-induced DNA-histone complex formation. Conclusions DNA-histone complex actively generated upon xenotransplantation is a novel target to inhibit coagulation and endothelial activation. To prevent tissue factor and adhesion molecule expression, a strategy to block soluble histone may be required in xenotransplantation. [ABSTRACT FROM AUTHOR]

Acute lung injury due to sulfur mustard (SM) inhalation causes the formation of airway fibrin casts that obstruct airways at multiple levels, leading to acute respiratory failure and death. These pathophysiological effects are seen in rodent models of acute SM vapor inhalation, as well as in human victims of acute SM inhalation. In rat models, the initial steps in activation of the coagulation system at extravascular sites depend on tissue factor (TF) expression by airway cells, especially in the microparticle fraction, and these effects can be inhibited by TF pathway inhibitor protein. Not only does the procoagulant environment of the acutely injured lung contribute to airway cast formation, but these lesions persist in airways because of the activation of multiple antifibrinolytic pathways, including plasminogen activator inhibitor-1, thrombin-activatable fibrinolysis inhibitor, and α2-antiplasmin. Airway administration of tissue plasminogen activator can overwhelm these effects and save lives by preventing fibrin-dependent airway obstruction, gas-exchange abnormalities, and respiratory failure. In human survivors of SM inhalation, fibrotic processes, including bronchiolitis obliterans and interstitial fibrosis of the lung, are among the most disabling chronic lesions. Antifibrotic therapies may prove useful in preventing either or both of these forms of chronic lung damage. [ABSTRACT FROM AUTHOR]

Tissue factor ( TF) expression in human cancers has been associated with a procoagulant state and facilitation of metastasis. This study was conducted in order to evaluate if TF was expressed in canine mammary tumours. Forty epithelial mammary tumours from 28 dogs were included. TF expression of the tumours was evaluated by immunohistochemistry using a polyclonal antibody against recombinant canine TF. In addition, thromboelastography, haemostatic and inflammatory parameters were evaluated in the patients. TF was recognized in 44% of benign and 58% of malignant tumours. TF localized to the cytoplasmic membrane of neoplastic luminal epithelial cells and/or diffusely in the cytoplasm. No association was found between TF expression and stage or grade of disease. A significant association between TF expression and antithrombin and plasminogen was found, and extensive TF expression was seen in a lymph node metastasis classified as anaplastic mammary carcinoma from a dog with concomitant disseminated intravascular coagulation ( DIC). [ABSTRACT FROM AUTHOR]

Tissue factor (TF) is a transmembrane glycoprotein that plays an essential role in hemostasis by activating coagulation. TF is also expressed by monocytes/macrophages as part of the innate immune response to infections. In the current study, we determined the role of TF expressed by myeloid cells during Mycobacterium tuberculosis ( M. tb) infection by using mice lacking the TF gene in myeloid cells (TFΔ) and human monocyte derived macrophages (MDMs). We found that during M. tb infection, a deficiency of TF in myeloid cells was associated with reduced inducible nitric oxide synthase (iNOS) expression, enhanced arginase 1 (Arg1) expression, enhanced IL-10 production and reduced apoptosis in infected macrophages, which augmented M. tb growth. Our results demonstrate that a deficiency of TF in myeloid cells promotes M2-like phenotype in M .tb infected macrophages. A deficiency in TF expression by myeloid cells was also associated with reduced fibrin deposition and increased matrix metalloproteases (MMP)-2 and MMP-9 mediated inflammation in M. tb infected lungs. Our studies demonstrate that TF expressed by myeloid cells has newly recognized abilities to polarize macrophages and to regulate M. tb growth. [ABSTRACT FROM AUTHOR]

Mycobacterium tuberculosis, the causative agent of tuberculosis, drives the formation of granulomas, structures in which both immune cells and the bacterial pathogen cohabit. The most abundant cells in granulomas are macrophages, which contribute as both cells with bactericidal activity and as targets for M. tuberculosis infection and proliferation during the entire course of infection. The mechanisms and factors involved in the regulation and control of macrophage microenvironment-specific polarization and plasticity are not well understood, as some granulomas are able to control bacteria growth and others fail to do so, permitting bacterial spread. In this issue of the European Journal of Immunology, Venkatasubramanian et al. [Eur. J. Immunol. 2016. 46: 464-479] show that mice lacking the tissue factor gene in myeloid cells have augmented M. tuberculosis growth and increased inflammation in the lungs. This suggests that tissue factor, an initiator of coagulation, is important for the generation of fibrin, which supports granuloma formation. This article demonstrates for the first time the involvement of tissue factor in inducing effective immunity against M. tuberculosis, and sheds new lights on the complex interplay between host inflammatory response, the coagulation system, and the control of M. tuberculosis infection. [ABSTRACT FROM AUTHOR]

Inflammation and hyperglycaemia are associated with a prothrombotic state. Cell-derived microparticles ( MPs) are the conveyors of active procoagulant tissue factor ( TF) and circulate at high concentration in diabetic patients. Liraglutide, a glucagon-like peptide ( GLP)-1 analogue, is known to promote insulin secretion and β-cell preservation. In this in vitro study, we examined the link between insulin impairment, procoagulant activity and plasma membrane remodelling, under inflammatory conditions. Rin-m5f β-cell function, TF activity mediated by MPs and their modulation by 1 μM liraglutide were examined in a cell cross-talk model. Methyl-β-cyclodextrine ( MCD), a cholesterol depletor, was used to evaluate the involvement of raft on TF activity, MP shedding and insulin secretion as well as Soluble N-éthylmaleimide-sensitive-factor Attachment protein Receptor ( SNARE)-dependent exocytosis. Cytokines induced a two-fold increase in TF activity at MP surface that was counteracted by liraglutide. Microparticles prompted TF activity on the target cells and a two-fold decrease in insulin secretion via protein kinase A ( PKA) and p38 signalling, that was also abolished by liraglutide. Large lipid raft clusters were formed in response to cytokines and liraglutide or MCD-treated cells showed similar patterns. Cells pre-treated by saturating concentration of the GLP-1r antagonist exendin (9-39), showed a partial abolishment of the liraglutide-driven insulin secretion and liraglutide-decreased TF activity. Measurement of caspase 3 cleavage and MP shedding confirmed the contribution of GLP-1r-dependent and -independent pathways. Our results confirm an integrative β-cell response to GLP-1 that targets receptor-mediated signalling and membrane remodelling pointing at the coupling of insulin secretion and inflammation-driven procoagulant events. [ABSTRACT FROM AUTHOR]

Airborne exposure to particulate matter with diameter < 10mcM (PM10) has been linked to an increased risk of thromboembolic events, but the mechanisms are not completely understood. The aim of this study was to evaluate the effect of PM10 phagocytosis on the release of procoagulant molecules in human differentiating macrophages, and that of PM10 inhalation in an experimental model in rats. Humanmonocytes were separated fromthe peripheral blood by the lymphoprep method, differentiated in vitro and treated with standard PM10 or vehicle. Sprague-Dawley rats were instilled intratracheally with PM10 or vehicle alone. The outcome was expression of proinflammatory genes and of tissue factor (TF). In human differentiating macrophages, PM10 exposure upregulated inflammatory genes, but most consistently induced TFmRNA and protein levels, but not TF protein inhibitor, resulting in increased TF membrane expression and a procoagulant phenotype. Differentiation towards the anti-inflammatory M2 phenotype inhibited PM10-mediated TF expression. TF induction required phagocytosis of PM10, whereas phagocytosis of inert particles was less effective. PM10 phagocytosis was associated with a gene expression profile consistent with intracellular retention of iron, inducing oxidative stress. Both PM10 and iron activated the stress kinases ERK1/2 pathway, involved in the induction of TF expression. In rats, alveolar exposure to PM10 was associated with pulmonary recruitment of inflammatory cells and resulted in local, but not systemic, induction of TF expression, which was sufficient to increase circulating TF levels. In conclusion, TF induction by differentiating lung macrophages, activated following phagocytosis, contributes to the increased risk of thromboembolic complications associated with PM10 exposure. [ABSTRACT FROM AUTHOR]

Aim: Less invasive therapies using mesenchymal stem cells (MSC) are being developed to treat patients with severe liver cirrhosis. MSC constitute a promising cell source for regenerative therapy and are frequently isolated from bone marrow (BMSC) or adipose tissue (ASC). Therefore, this study assessed the characteristics of these two cell types and their safety for cell infusion. Methods: In vitro, exhaustive genetic analysis was performed using human (h)BMSC and hASC. Subsequently, the expression of mRNA and protein was evaluated. In vivo, mouse (m)BMSC or mASC was infused into serial mice via the peripheral vein, and 24-h survival rate, prothrombin time and cause of death were analyzed. Results: On polymerase chain reaction, western blotting, enzyme-linked immunoassay and fluorescence-activated cell sorting, tissue factor was found to be expressed at higher levels in hASC than in hBMSC. Prothrombin time in mice infused with mASC (>120 s) was markedly longer than that of untreated mice (6.5 ± 1.7 s) and that of mice infused with BMSC (6.7 ± 0.8 s) (P<0.001), indicating that pro-coagulation activity was potently enhanced after ASC infusion. The 24-h survival rates in the mASC- and mBMSC-infused groups were 46.4% (13/28) and 95.5% (21/22), respectively; in the former, the rate decreased with increasing number of infused mASC. This cell number-dependent effect was not observed with mBMSC. A histopathological analysis of mice that died immediately following mASC infusion revealed multiple thrombi in the blood vessels of the lungs. Conclusion: These results indicate that BMSC are a superior and safer cell source for regenerative therapy. [ABSTRACT FROM AUTHOR]

Recent epidemiologic data suggest that sickle cell trait (Hb AS; AS) is a risk factor for venous thromboembolism. We conducted an exploratory study of healthy subjects with AS under baseline conditions to determine whether a chronic basal hyperactivation of coagulation exists, and if so, what mechanism(s) contribute to this state. Eighteen healthy AS individuals were compared to 22 African-American controls with a normal haemoglobin profile (Hb AA; AA) and 17 patients with sickle cell disease (Hb SS; SS). Plasma thrombin-antithrombin complexes and D-dimer levels were elevated in AS relative to AA patients ( P = 0·0385 and P = 0·017, respectively), and as expected, were much higher in SS versus AA ( P < 0·0001 for both). Thrombin generation in platelet poor plasma was indistinguishable between AA and AS subjects, whereas a paradoxical decrease in endogenous thrombin potential was observed in SS ( P ≤ 0·0001). Whole blood tissue factor was elevated in SS compared to AA ( P = 0·005), but did not differ between AA and AS. Plasma microparticle tissue factor activity was non-significantly elevated in AS ( P = 0·051), but was clearly elevated in SS patients ( P = 0·004) when compared to AA controls. Further studies in larger cohorts of subjects with sickle cell trait are needed to confirm the results of this preliminary investigation. [ABSTRACT FROM AUTHOR]

Tissue factor (TF) triggers the extrinsic blood coagulation cascade and is highly expressed in various types of cancer. In this study, we investigated the antitumor effect of an antibody-drug conjugate (ADC) consisting of an anti-TF monoclonal antibody and monomethyl auristatin E (MMAE). MMAE was conjugated to an anti-human TF or anti-mouse TF antibody using a valine-citrulline linker that could be potentially hydrolyzed by cathepsin B in the acidic environment of the lysosome. The cytotoxic and antitumor effects of the ADCs against four pancreatic cancer cell lines were analyzed. Both the ADC with the anti-human TF antibody and that with the anti-mouse TF antibody were stable under physiological conditions. The anti-human ADC was internalized in TF-expressing human tumor cell lines, followed by effective MMAE release. The half maximal inhibitory concentration (IC50) of MMAE was approximately 1 nM for all of the cell lines used. Meanwhile, the IC50 of anti-human ADC was 1.15 nM in the cell lines showing high TF expression, while exceeding 100 nM in the cells showing low TF expression levels. Anti-human ADC with passive and active targeting ability exerted significant suppression of tumor growth as compared to that observed in the saline group ( p < 0.01). Also significant tumor growth suppressions were seen at the anti-mouse ADC and control ADC groups compared to the saline group ( p < 0.01) due to EPR effect. Because various clinical human cancers express highly amount of TF, this new anti-TF ADC may deserve a clinical evaluation. [ABSTRACT FROM AUTHOR]

Tissue Factor (TF) is an evolutionary conserved glycoprotein, which is of immense importance for a variety of biologic processes. TF is expressed in two naturally occurring protein isoforms, membrane-bound 'full-length' (fl)TF and soluble alternatively spliced (as)TF. The TF isoform expression is differentially modulated on post-transcriptional level via regulatory factors, such as serine/arginine-rich (SR) proteins, SR protein kinases and micro (mi)RNAs. Both isoforms mediate a variety of physiologic- and pathophysiologic-relevant functions, such as thrombogenicity, angiogenesis, cell signaling, tumor cell proliferation and metastasis. In this review, we will depict the main mechanisms regulating the TF isoform expression in cancer and under other pathophysiologic-relevant conditions. Moreover, we will summarize and discuss the latest findings regarding the role of TF and its isoforms in cancer biology. [ABSTRACT FROM AUTHOR]

Introduction When investigating coagulation assays to measure the effect of infused prothrombin (FII) in in vivo coagulopathy models, we found that addition of FII, plasma-derived human FII (pd- hFII) or recombinant human FII (r- hFII), to normal plasma resulted in a concentration-dependent increase in prothrombin time (PT) initiated with Innovin®. Methods The effect on PT by addition to plasma of either pd- hFII or r- hFII, using different commercial PT reagents, was studied both by turbidimetry and viscometry. Result Addition of FII to plasma resulted in increased PT when initiated with Innovin®: PT increased with 20% by doubling the concentration. The prolongation of PT became more pronounced with 2-6000 times diluted Innovin®. However, by adjustment of the final free Ca2+ concentration in the assay with diluted Innovin® from 8.3 to 1.3 mmol/L, no FII-dependent increase in PT was found. In contrast, no prolongation of PT was found with other commercial PT reagents. A KM= 3 nmol/L was obtained with pd- hFII, respectively, r- hFII with FII-depleted plasma using Thromborel® to initiate PT. Conclusion At normal plasma concentration of FII, addition of FII should not have an effect on PT. The prolonged PT with Innovin®, but not with other PT reagents, at supranormal FII concentration is an artefact. [ABSTRACT FROM AUTHOR]

Background Studies of some human prothrombotic diseases suggest that phosphatidylserine-positive ( PS+) and tissue factor-positive ( TF+) microparticles ( MPs) might play a role in the pathogenesis of thrombosis or serve as biomarkers of thrombotic risk. Hypothesis/Objectives To determine if circulating levels of PS+ MP and procoagulant activity ( PCA) associated with PS+ MPs and TF+ MPs are increased in dogs with IMHA. Animals Fifteen dogs with primary or secondary IMHA and 17 clinically healthy dogs. Methods Prospective case-controlled observational study. Circulating PS+ MPs were measured by flow cytometry. PCA associated with PS+ MPs and TF+ MPs was measured by thrombin and Factor Xa generating assays, respectively. Results Circulating numbers of PS+ MPs were not significantly higher in dogs with IMHA [control median 251,000/μL (36,992-1,141,250/μL); IMHA median 361,990/μL (21,766-47,650,600/μL) P = .30]. However, PS+ MP PCA [control median 2.2 (0.0-16.8) nM PS eq; IMHA median 8.596, (0-49.33 nM PS eq) P = .01] and TF+ MP PCA [control median 0.0, (0.0-0.0 pg/mL); IMHA median 0.0; (0-22.34 pg/mL], P = .04) were increased. Intravascular hemolysis, which we showed might increase PS+ and TF+ MP PCA, was evident in 3 of 5 dogs with PS+ MP PCA and 2 of 4 dogs with TF+ MP PCA higher than controls. Underlying disease in addition to IMHA was detected in 1 of 5 dogs with PS+ PCA and 3 of 4 dogs with TF+ MP PCA higher than controls. Conclusions and Clinical Importance TF+ and PS+ MP PCA is increased in some dogs with IMHA. Further studies that determine if measuring TF+ and PS+ MP PCA can help identify dogs at risk for thrombosis are warranted. [ABSTRACT FROM AUTHOR]

For the creation of a successful antibody-drug conjugate ( ADC), both scientific and clinical evidence has indicated that highly toxic anticancer agents ( ACA) should be conjugated to a monoclonal antibody ( mAb) to administer a reasonable amount of ADC to patients without compromising the affinity of the mAb. For ordinary ACA, the conjugation of a mAb to ACA-loaded micellar nanoparticles is clinically applicable. Tissue factor ( TF) is often overexpressed in various cancer cells and tumor vascular endothelium. Accordingly, anti- TF- NC-6300, consisting of epirubicin-incorporating micelles ( NC-6300) conjugated with the F(ab')2 of anti- TF mAb was developed. The in vitro and in vivo efficacy and pharmacokinetics of anti- TF- NC-6300 were compared to NC-6300 using two human pancreatic cancer cell lines, Bx PC3 (high TF expression) and SUIT2 (low TF expression), and a gastric cancer cell line, 44As3 (high TF expression). The intracellular uptake of epirubicin was faster and greater in Bx PC3 cells treated with anti- TF- NC-6300, compared with NC-6300. Anti- TF- NC-6300 showed a superior antitumor activity in Bx PC3 and 44As3 xenografts, compared with NC-6300, while the activities of both micelles were similar in the SUIT2 xenograft. A higher tumor accumulation of anti- TF- NC-6300 compared to NC-6300 was seen, regardless of the TF expression levels. However, anti- TF- NC-6300 appeared to be localized to the tumor cells with high TF expression. These results indicated that the enhanced antitumor effect of anti- TF- NC6300 may be independent of the tumor accumulation but may depend on the selective intratumor localization and the preferential internalization of anti- TF- NC-6300 into high TF tumor cells. [ABSTRACT FROM AUTHOR]

Background and purpose Stroke is an important cause of death and disability throughout the world. Microparticles play a cardinal role in vascular hemostasis. The primary aim of this study was to evaluate the procoagulant activity of microparticles and levels of tissue-factor-bearing microparticles ( MPs- TF), tissue factor ( TF) and tissue factor pathway inhibitor ( TFPI) in patients with acute ischaemic stroke. Methods Seventy-three patients with a diagnosis of acute ischaemic stroke were included. Venous blood samples were drawn on the first day and the seventh day after stroke onset. Plasma microparticles, MPs- TF, TF and TFPI were determined by enzyme-linked immunosorbent assay. Assessment variables were timing of blood collection, type of stroke treatment, presence or absence of diabetes mellitus and hypertension, and scores on the National Institutes of Health Stroke Scale together with scores on the modified Rankin Scale. Results Whilst MPs-TF and TFPI levels of stroke subjects were significantly higher (median, 1.63 vs. 0.73 pg/ml; median, 114.26 vs. 78.60 ng/ml, respectively), TF levels in the plasma of stroke patients were significantly lower (median, 82.27 vs. 97.80 pg/ml) than those of healthy individuals. Lower levels of TF were detected in patients with severe stroke in comparison with patients with mild stroke. Moreover, the data also showed that in stroke patients not treated with alteplase the activity of microparticles was significantly higher 1 week after diagnosis in comparison with the activity at the time of diagnosis. Conclusion Our findings suggest that patients with acute ischaemic stroke have increased generation of MPs-TF. Nevertheless, further studies are needed in order to confirm such inference. [ABSTRACT FROM AUTHOR]

Venous thromboembolism constitutes one of the main causes of death during the progression of a cancer. We previously demonstrated that tissue factor (TF)-bearing cancer cell-derived microparticles accumulate at the site of injury in mice developing a pancreatic cancer. The presence of these microparticles at the site of thrombosis correlates with the size of the platelet-rich thrombus. The objective of this study was to determine the involvement of TF expressed by cancer cell-derived microparticles on thrombosis associated with cancer. We observed that pancreatic cancer cell derived microparticles expressed TF, its inhibitor tissue factor pathway inhibitor (TFPI) as well as the integrins αvβ1 and αvβ3. In mice bearing a tumor under-expressing TF, a significant decrease in circulating TF activity associated with an increase bleeding time and a 100-fold diminished fibrin generation and platelet accumulation at the site of injury were observed. This was mainly due to the interaction of circulating cancer cell-derived microparticles expressing TFPI with activated platelets and fibrinogen. In an ectopic model of cancer, treatment of mice with Clopidogrel, an anti-platelet drug, decreased the size of the tumors and restored hemostasis by preventing the accumulation of cancer cell-derived microparticles at the site of thrombosis. In a syngeneic orthotopic model of pancreatic cancer Clopidogrel also significantly inhibited the development of metastases. Together, these results indicate that an anti-platelet strategy may efficiently treat thrombosis associated with cancer and reduce the progression of pancreatic cancer in mice. [ABSTRACT FROM AUTHOR]

Although the association between cancer and venous thromboembolism (VTE) has long been known, the mechanisms are poorly understood. Circulating tissue factor–bearing extracellular vesicles have been proposed as a possible explanation for the increased risk of VTE observed in some types of cancer. The International Society for Extracellular Vesicles (ISEV) and International Society on Thrombosis and Haemostasis (ISTH) held a joint Educational Day in April 2014 to discuss the latest developments in this field. This review discusses the themes of that event and the ISEV 2014 meeting that followed. [ABSTRACT FROM AUTHOR]

Tissue factor ( TF), which serves as the initiator of the extrinsic blood coagulation cascade, has been found to be overexpressed in various solid tumors, especially brain tumors, pancreatic cancer, and gastric cancer. Overexpression of TF is considered to contribute to the high incidence of thrombotic complications and poor prognosis in patients with such cancers. Therefore, detection or targeting of TF may be a promising approach for the diagnosis and treatment of solid tumors that are known to overexpress the protein. Here, we used the recombinant DNA technology to develop an anti- TF single-chain Fv (scFv) of small size and high affinity for its target. The biochemical characteristics of the anti- TF scFv were evaluated using surface plasmon resonance ( SPR) sensing and flow cytometry. The data obtained showed that the affinity of the anti- TF scFv was 2.04 × 10−8 ( KD), and that the protein showed significant binding to the cancer cells. Then, Alexa 647-labeled anti- TF scFv and anti- TF IgG were administered to mice bearing chemically induced spontaneous tumors. The maximum tumor to background ratios of anti- TF scFv and anti- TF IgG were obtained 3 and 24 h after the injections, respectively. This study indicates anti- TF scFv may be suitable as an imaging probe for the diagnosis of solid tumors. [ABSTRACT FROM AUTHOR]

Formation of the factor VIIa (FVIIa)-tissue factor (TF) complex triggers the blood coagulation cascade. Using a structure-based rationale, we investigated how the length of the linker region between the two epidermal growth factor (EGF)-like domains in FVIIa influences TF binding and the allosteric activity enhancement, as well as the interplay between the γ-carboxyglutamic acid (Gla)-containing and protease domains. Removal of two residues from the native linker was compatible with normal cofactor binding and accompanying stimulation of the enzymatic activity, as was extension by two (Gly-Ser) residues. In sharp contrast, truncation by three or four residues abolished the TF-mediated stabilization of the active conformation of FVIIa and abrogated TF-induced activity enhancement. In addition, FVIIa variants with short linkers associated 80-fold slower with soluble TF (sTF) as compared with wild-type FVIIa, resulting in a corresponding increase in the equilibrium dissociation constant. Molecular modeling suggested that the shortest FVIIa variants would have to be forced into a tense and energetically unfavorable conformation in order to be able to interact productively with TF, explaining our experimental observations. We also found a correlation between linker length and the residual intrinsic enzymatic activity of Ca2+-free FVIIa; stepwise truncation resulting in gradually higher activity with des(83-86)-FVIIa reaching the level of Gla-domainless FVIIa. The linker appears to determine the average distance between the negatively charged Gla domain and a structural element in the protease domain, presumably of opposite charge, and proximity has a negative impact on apo-FVIIa activity. [ABSTRACT FROM AUTHOR]

Hereditary angioedema ( HAE) presents as severe angioedema, which is mostly due to the C1 inhibitor ( C1- INH) gene mutations. Environmental factors, minor trauma and oral contraceptives have been reported to induce angioedema attack, but the trigger may often be uncertain. Activated factor XII controlled by C1- INH facilitates bradykinin generation and also regulates coagulation cascade, but the relationship between edema formation and coagulation is still unclear. We have described a 35-year-old female patient with HAE, presenting with frequent angioedema attacks in the absence of an apparent triggering factor. She showed higher levels of FDP and D-dimer during angioedema than those in remission. In addition, tissue factor ( TF), an initiator of the extrinsic coagulation cascade, was expressed on the surface of monocytes. It was significantly higher than that of monocytes from healthy controls and tends to further increase during attacks. The expression of TF on monocytes may play a role in the induction of angioedema attacks in HAE by activating the coagulation pathway in association with reduced functions of C1- INH. [ABSTRACT FROM AUTHOR]