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Antithrombin and tissue factor pathway inhibitor (TFPI) provide different anticoagulant mechanisms. Having established a potent anticoagulant role of cultured human umbilical vein endothelial cells in vessel-on-a-chip microfluidic models, we now investigated how these cells modulated thrombin generation under stasis through antithrombin and TFPI pathways. We observed that endothelial monolayers in 96 well-plates strongly delayed and suppressed the thrombin generation process induced by tissue factor, regardless of the presence of whole blood, platelet-rich plasma or platelet-free plasma. Intervention studies indicated that the blocking of heparin-like proteoglycans with polybrene or protamine sulphate, similarly as the absence of antithrombin in plasma, reverted the endothelial anticoagulant activity. Heparinase treatment of the cells also reduced the anticoagulant potential. Furthermore, the presence of andexanet-alpha (inactivated factor Xa) and an anti-TFPI antibody were able to revert the endothelial effects. Jointly, these data point to additive anticoagulant mechanisms of endothelial cells through surface-expressed heparin-like proteoglycans and TFPI, both contributing to thrombin inhibition., Competing Interests: Declaration of competing interest H.M., D.H., M.R. and B.d.L. are employees of the Synapse Research Institute Maastricht (member of the Stago Diagnostic group), P.G.d.G. and J.W.M.H. are advisors of the same institute. The other authors do not report a conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Introduction: Coagulation activation on medical devices remains a significant problem as it can lead to dramatic thromboembolic complications. Understanding its poorly described mechanisms and finding optimal pharmacological prevention means is crucial to improve patient safety., Methods: We developed an in vitro model to study thrombin generation (TG) initiated by the contact of plasma with the surface of catheters. Interventional cardiology catheters were cut into segments and inserted in the bottom of multi-well plates; TG was then measured with the calibrated automated thrombogram (CAT). Model performance (analytical, intra- and inter-individual variability) was investigated and compared with activation of thrombin generation by tissue factor (TF) or contact pathway activator (ellagic acid), in the presence (PRP) and absence (PPP) of platelets. Model response to unfractionated heparin (UFH) was also assessed., Results: TG was greater when measured in presence of catheter segments, compared to conditions without activators. The analytical variability of the model was good (CV ≤ 5 %), both with PPP and PRP. Intra-individual variability was between 15 and 30 % with PPP and between 10 and 15 % with PRP. Inter-individual variability was between 15 and 30 % with both kinds of plasma samples. The analytical performance of the catheter-initiated TG model was equivalent to that observed when TG was initiated with TF or ellagic acid. Catheter-initiated TG was measurable until 0.1 IU/mL UFH with PPP and until 1.0 IU/mL UFH with PRP, highlighting the crucial requirement of platelets., Conclusion: Our model is suitable for studying TG initiated with catheters. Inhibition of TG by UFH is overestimated in the absence of platelets., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Michael hardy reports financial support was provided by Fund for Scientific Research. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Conflict of interest MH, BR, OX, SL, TL: none. JD is the CEO and founder of QUALIblood s.a., a contract research organization manufacturing the DP-Filter, is a coinventor of the DP-Filter (patent application number: PCT/ET2019/052903) and reports personal fees from Daiichi-Sankyo, Mithra Pharmaceuticals, Diagnostica Stago, Roche and Roche Diagnostics, outside the submitted work. FM reports institutional fees from Stago, Werfen, Nodia, Roche Sysmex and Bayer. He also reports speaker fees from Boehringer-Ingelheim, Bayer Healthcare, Bristol-Myers Squibb-Pfizer, Diagnostica Stago, Sysmex and Aspen, all outside the submitted work., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Toddalia asiatica (L.) Lam. (TA) is a traditional folk medicine of ethnic minorities in the southwest of China. It is widely used in the treatment of dispersing blood stasis and activating blood. However, the effective substance and pharmacological mechanism have not been fully elucidated. The zebrafish larvae were treated with Phenylhydrazine (PHZ) to establish a thrombus model, and the staining intensity of zebrafish red blood cells was analyzed. The antithrombotic activity of TA was verified for the first time, and it was found that the inhibition rate of TA on thrombosis was up to 60.85 %. The chemical ingredients of TA were collected by combining UPLC-HRMS analysis and the literature research. Network pharmacology revealed that six key targets were obtained, which including TNF, AKT1, EGFR, PTGS2, PPARG, and IFNG. It showed that the PI3K-Akt pathway was a core signaling pathway. Coagulation factor III(TF), playing an important role in the process of hemostasis and thrombosis, which ranks high in the PPI network. Moreover, the results of molecular docking showed that the active components had a strong binding force with TF, which indicated that TF might be the key target of TA in treating thrombosis. In vitro experiments showed that TA could inhibit TNF-α-induced high expression of TF in EA.hy926 cells. In addition, TA could inhibit TNF-α-activated expression of Akt, IκBα and P65 protein phosphorylation in PI3K-Akt pathway. The results showed that TA had antithrombotic activity and exerted an antithrombotic effect by inhibiting the expression of TF through the PI3K-Akt-NF-κB signaling pathway., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024. Published by Elsevier B.V.)

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., (© 2024 John Wiley & Sons Ltd.)

Background: Neutrophils are known to externalize their DNA and intracellular contents to neutralize invading pathogens. This process may enhance blood coagulation during inflammation. TFPI binds to extracellular DNA and may be citrullinated by peptidylarginine deiminase 4 (PAD4). Citrullination of TFPI reduces its anticoagulant activity towards factor Xa, but appeared to retain its inhibition of tissue factor (TF)-triggered thrombin generation, indicating a differential regulation of TFPI functions by PAD4., Aim: This work aims to study effects of citrullination of TFPI alpha on the inhibition of FXa, FVIIa/TF, and the cofactor activity of protein S., Methods: The effect of TFPI citrullination on inhibition of FXa and FVIIa/TF was measured by chromogenic assays using purified components and by calibrated automated thrombography. Interaction with protein S was assessed by SPR and solid-phase binding assays using immobilized protein S, recombinant TFPI, and synthetic TFPI domains., Results: Citrullination of TFPI abolished its ability to inhibit FXa- and FXIa-triggered thrombin generation. However, its impaired inhibition of TF-triggered thrombin generation was still enhanced by protein S. Chromogenic assays revealed that citrullinated TFPI was essentially inactive as an inhibitor of the FVIIa-TF complex in the absence of protein S, but partially restored by protein S. Interaction studies revealed that binding of citrullinated TFPI to protein S was reduced approximately fourfold., Conclusion: Citrullinated TFPI shows impaired natural anticoagulant activity. While anti-FXa activity is essentially absent, its anti-TF/FVIIa activity can still be enhanced by protein S. This enhancement is incomplete however, as protein S binding to citrullinated TFPI is impaired., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background and Aims: 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., Methods: 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., Results: 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)., Conclusions: 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., (© 2024 The Author(s). Liver International published by John Wiley & Sons Ltd.)

Acute lung injury (ALI) resulting from bacterial infection poses a significant risk, and its etiology involves the complex interplay of harmful immune responses and blood coagulation. Despite this understanding, the roles and mechanisms of tissue factor pathway inhibitor (TFPI) in LPS-induced ALI remain insufficiently elucidated. In this study, we aimed to explore the effects of TFPI in LPS-induced ALI. Our investigations revealed that TFPI exerts multiple beneficial effects in LPS-induced ALI. Specifically, TFPI reduces microvascular permeability, Myeloperoxidase (MPO) activity, and cytokine production while inhibiting blood coagulation.Moreover, TFPI demonstrates the capacity to promote proliferation and suppress apoptosis in Human microvascular endothelial cells (HMEC-1) and Human umbilical vein endothelial cells (HUVEC) through the inhibition of the caspase pathway and mitochondrial apoptosis pathway.Furthermore, our findings indicate a correlation between tissue factor (TF) and TFPI expression, with TFPI regulation observed in HMEC-1 cells following LPS treatment. This novel insight suggests that TFPI plays a regulatory role in TF expression. Overall, the protective effect of TFPI on LPS-induced ALI is unveiled by its ability to enhance endothelial cell proliferation and inhibit apoptosis through the modulation of caspase and Bcl-2/Bax pathways. These results underscore the potential of TFPI as a promising therapeutic target for ALI treatment., Competing Interests: Declaration of Competing Interest ☒ The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Background & Aims: The underlying mechanisms and clinical impact of portal microthrombosis in severe COVID-19 are unknown. Intrapulmonary vascular dilation (IPVD)-related hypoxia has been described in severe liver diseases. We hypothesised that portal microthrombosis is associated with IPVD and fatal respiratory failure in COVID-19., Methods: Ninety-three patients who died from COVID-19 were analysed for portal microvascular damage (histology), IPVD (histology and chest-computed tomography, CT), and hypoxemia (arterial blood gas). Seventeen patients who died from COVID-19-unrelated pneumonia served as controls. Vascular lesions and microthrombi were phenotyped for endothelial (vWF) and pericyte (αSMA/PDGFR-β) markers, tissue factor (TF), viral spike protein and nucleoprotein (SP, NP), fibrinogen, and platelets (CD41a). Viral particles in vascular cells were assessed by transmission electron microscopy. Cultured pericytes were infected with SARS-CoV-2 to measure TF expression and tubulisation of human pulmonary microvascular endothelial cells was assessed upon vWF treatment., Results: IPVD was present in 16/66 patients with COVID-19, with available liver and lung histology, and was associated with younger age (62 vs. 78 years-old), longer illness (25 vs. 14 days), worsening hypoxemia (PaO 2 /FiO 2 from 209 to 89), and an increased requirement for ventilatory support (63% vs. 22%) compared to COVID-19/Non-IPVD. IPVD, absent in controls, was confirmed by chest CT. COVID-19/IPVD liver histology showed portal microthrombosis in >82.5% of portal areas, with a thicker wall of αSMA/PDGFR-β + /SP + /NP + pericytes compared with COVID-19/Non-IPVD. Thrombosed portal venules correlated with αSMA + area, whereas infected SP + /NP + pericytes expressed TF. SARS-CoV-2 viral particles were observed in portal pericytes. In vitro SARS-CoV-2 infection of pericytes upregulated TF and induced endothelial cells to overexpress vWF, which expanded human pulmonary microvascular endothelial cell tubules., Conclusions: SARS-CoV-2 infection of liver pericytes elicits a local procoagulant response associated with extensive portal microthrombosis, IPVD and worsening respiratory failure in fatal COVID-19., Impact and Implications: Vascular involvement of the liver represents a serious complication of COVID-19 infection that must be considered in the work-up of patients with long-lasting and progressively worsening respiratory failure, as it may associate with the development of intrapulmonary vascular dilations. This clinical picture is associated with a procoagulant phenotype of portal venule pericytes, which is induced by SARS-CoV-2 infection of pericytes. Both observations provide a model that may apply, at least in part, to other vascular disorders of the liver, featuring obliterative portal venopathy, similarly characterised at the clinical level by development of hypoxemia and at the histological level by phlebosclerosis and reduced calibre of the portal vein branches in the absence of cirrhosis. Moreover, our findings shed light on an overlooked player in the pathophysiology of thrombosis, i.e. pericytes, which may present a novel therapeutic target., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have obvious advantages over MSC therapy. But the strong procoagulant properties of MSC-EVs pose a potential risk of thromboembolism, an issue that remains insufficiently explored. In this study, we systematically investigated the procoagulant activity of large EVs derived from human umbilical cord MSCs (UC-EVs) both in vitro and in vivo. UC-EVs were isolated from cell culture supernatants. Mice were injected with UC-EVs (0.125, 0.25, 0.5, 1, 2, 4 μg/g body weight) in 100 μL PBS via the tail vein. Behavior and mortality were monitored for 30 min after injection. We showed that these UC-EVs activated coagulation in a dose- and tissue factor-dependent manner. UC-EVs-induced coagulation in vitro could be inhibited by addition of tissue factor pathway inhibitor. Notably, intravenous administration of high doses of the UC-EVs (1 μg/g body weight or higher) led to rapid mortality due to multiple thrombus formations in lung tissue, platelets, and fibrinogen depletion, and prolonged prothrombin and activated partial thromboplastin times. Importantly, we demonstrated that pulmonary thromboembolism induced by the UC-EVs could be prevented by either reducing the infusion rate or by pre-injection of heparin, a known anticoagulant. In conclusion, this study elucidates the procoagulant characteristics and mechanisms of large UC-EVs, details the associated coagulation risk during intravenous delivery, sets a safe upper limit for intravenous dose, and offers effective strategies to prevent such mortal risks when high doses of large UC-EVs are needed for optimal therapeutic effects, with implications for the development and application of large UC-EV-based as well as other MSC-EV-based therapies., (© 2024. The Author(s), under exclusive licence to Shanghai Institute of Materia Medica, Chinese Academy of Sciences and Chinese Pharmacological Society.)

Background: Coagulopathy is part of the pathological host response to infection in sepsis. Higher plasma concentrations of both tissue factor (TF) and tissue factor pathway inhibitor (TFPI) are associated with occurrence of disseminated intravascular coagulation (DIC), multi-organ dysfunction and increased mortality in patients with sepsis. Currently no treatment approaches specifically targeting this axis are available. We hypothesize that therapeutic plasma exchange (TPE) might limit this coagulopathy by restoring the balance of plasma proteins., Methods: This was a pooled post-hoc biobank analysis including 51 patients with early (shock onset < 24 h) and severe (norepinephrine dose > 0.4 μg/kg/min) septic shock, who were either receiving standard of care treatment (SOC, n = 14) or SOC + one single TPE (n = 37). Plasma concentrations of TF and TFPI were measured both at- and 6 h after study inclusion. The effect of TPE on concentrations of TF and TFPI was investigated and compared to SOC patients. Further, baseline TF and TFPI concentrations were used to modulate and predict clinical response to adjunctive TPE, indicated by longitudinal reduction of lactate concentrations over the first 24 h following study inclusion., Results: TPE led to a significant reduction in circulating concentrations of both TF and TFPI while no difference was observed in the SOC group. Relative change of TF within 6 h was + 14 (-0.8 to + 30.4) % (p = 0.089) in the SOC and -18.3 (-32.6 to -2.2) % (p < 0.001) in the TPE group (between group p < 0.001). Similarly, relative change of TFPI was + 14.4 (-2.3 to + 30.9) % (p = 0.076) in the SOC and -20 (-32.8 to -7.9) % (p < 0.001) in the TPE group (between group p = 0.022). The ratio of TF to TFPI remained unchanged in both SOC and TPE groups. SOC patients exhibited an increase in lactate over the initial 24 h when TF and TFPI concentrations were higher at baseline. In contrast, patients undergoing TPE experienced a sustained longitudinal reduction of lactate concentrations across all levels of baseline TF and TFPI elevations. In a multivariate mixed-effects model, higher baseline TF (p = 0.003) and TFPI (p = 0.053) levels led to greater longitudinal lactate concentration reduction effects in the TPE group., Conclusions: Adjunctive TPE in septic shock is associated with a significant removal of both TF and TFPI, which may contribute to the early hemodynamic improvement observed in septic shock patients receiving TPE. Higher baseline TF (and TFPI) plasma concentrations were identified as a putative predictor of treatment response that could be useful for predictive enrichment strategies in future clinical trials., (© 2024. The Author(s).)

Objective: Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is a significant pulmonary complication of RA. This study tried to elucidate the mechanisms enhancing inflammation and causing lung injury in RA-ILD, focusing on the role of neutrophil extracellular traps (NETs). The study also investigated the potential benefits of nintedanib in advanced disease., Methods: Nine RA-ILD patients and nine healthy controls were included in the study. Inflammatory markers in patients' circulation were evaluated with immunoassays. The formation of NETs was examined using a citrullinated histone H3 (CitH3) ELISA and cell immunofluorescence. Inflammatory proteins expressed in neutrophils/NETs were studied with real-time qPCR and NET ELISA. To assess the effect of nintedanib, an intracellular tyrosine kinase inhibitor with antifibrotic properties, in RA-ILD a paired study was conducted in five patients before treatment administration and 16 weeks later., Results: The soluble terminal complement complex sC5b-9 and the levels of CitH3 were significantly elevated in patients with RA-ILD, compared to healthy controls. In addition, neutrophils isolated from RA-ILD patients released NETs enriched with tissue factor and interleukin-17A. Inflammatory NETs had a dynamic role, increasing the fibrotic potential of human pulmonary fibroblasts (HPFs). On the other hand, nintedanib treatment decreased NETs and sC5b-9 levels in RA-ILD patients., Conclusion: The findings propose an interplay between circulating NETs and HPFs, establishing the immunofibrotic aspects of RA-ILD. They also support the effectiveness of nintedanib in reducing key pathological processes of the disease. Further research is needed to fully understand these mechanisms and optimize treatment strategies for RA-ILD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Venetsanopoulou, Ntinopoulou, Papagianni, Koletsos, Voulgari and Chrysanthopoulou.)

Background: Ulcerative colitis (UC) increases the risk for venous thromboembolism. Tissue factor (TF) initiates the extrinsic coagulation pathway (ECP)., Aims: To investigate the correlation of UC severity with latent ECP activation and TF expression in primary colonic stromal cells (PCSC)., Methods: In plasma of 38 UC patients (31 males, disease duration 151 ± 25 months) and 28 healthy controls, exosomes and microparticles (EM) were counted. Moreover, TF protein concentration, activities of EM-bound TF (EM-TFa) and coagulation factor VII (FVIIa) were assessed. In PCSC in culture, TF mRNA (F3) from 12 patients with active UC and 7 controls was evaluated., Results: UC patients had 4- and 3.7- times more exosomes and microparticles, respectively, than controls. TF protein in UC was correlated with several disease severity indices, such as partial Mayo score (pMs; r 0.443), albumin (- 0.362), ESR (0.353), PLT (0.575), and endoscopic Ms (eMs 0.468). EM-TFa was also significantly higher in UC and was correlated to SIBDQ (- 0.64), albumin (- 0.624), disease extent and eMs (0.422). Refractory-to-treatment patients had significantly higher TF protein, EM-TFa and FVIIa. Even within responders, the need for steroids or biologics correlated with a 2.2-times higher EM-TFa. PCSC from active UC maintained higher F3 than controls, which was correlated to pMs (0.56), albumin (- 0.543) and eMs. Treatment with cytokines further upregulated F3. P for all comparisons was < 0.05., Conclusion: Low-grade activation of the ECP associates with clinical, endoscopic UC activity and response to treatment. TF in PCSC mirrors its systemic activity and points to them as a source., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Scientific and clinical interest in extracellular vesicles (EVs) is growing. EVs that expose tissue factor (TF) bind factor VII/VIIa and can trigger coagulation. Highly procoagulant TF-exposing EVs are detectable in the circulation in various diseases, such as sepsis, COVID-19, or cancer. Many in-house and commercially available assays have been developed to measure EV-TF activity and antigen, but only a few studies have compared some of these assays., Objectives: The International Society on Thrombosis and Haemostasis Scientific and Standardization Committee Subcommittee on Vascular Biology initiated a multicenter study to compare the sensitivity, specificity, and reproducibility of these assays., Methods: Platelet-depleted plasma samples were prepared from blood of healthy donors. The plasma samples were spiked either with EVs from human milk or EVs from TF-positive and TF-negative cell lines. Plasma was also prepared from whole human blood with or without lipopolysaccharide stimulation. Twenty-one laboratories measured EV-TF activity and antigen in the prepared samples using their own assays representing 18 functional and 9 antigenic assays., Results: There was a large variability in the absolute values for the different EV-TF activity and antigen assays. Activity assays had higher specificity and sensitivity compared with antigen assays. In addition, there was a large intra-assay and interassay variability. Functional assays that used a blocking anti-TF antibody or immunocapture were the most specific and sensitive. Activity assays that used immunocapture had a lower coefficient of variation compared with assays that isolated EVs by high-speed centrifugation., Conclusion: Based on this multicenter study, we recommend measuring EV-TF using a functional assay in the presence of an anti-TF antibody., Competing Interests: Declaration of competing interests F.D.-G. and R.L. filed a patent on microvesicle fibrinolytic activity licensed to Stago and obtained a common grant within the framework of the excellence program innovative tests to customize antiplatelet therapy in chronic kidney disease with acute coronary syndrome. The remaining authors declare no competing financial interests., (Copyright © 2024. Published by Elsevier Inc.)

Tissue factor (TF) possesses additional physiological functions beyond initiating the coagulation cascade. Cellular signals initiated by cellular TF or on contact with TF‑containing microvesicles, contribute to wound healing through regulating a number of cellular properties and functions. TF regulates the cell cycle checkpoints, however the underlying signalling mechanisms have not been determined. Endothelial (human dermal blood endothelial cells and human umbilical vein endothelial cells) and epithelial [human telomerase reverse transcriptase‑human pancreatic nestin‑expressing ductal cells (hTERT‑HPNE) and AsPC‑1] cells were exposed to different concentrations of recombinant TF, and the influence on G1/S checkpoint regulators examined. Short‑term exposure to a lower concentration of TF promoted increased p16 INKa and decreased p21 CIP1/WAF1 expression, together with higher early region 2 binding factor (E2F) transcriptional activity and increased phosphorylation of Thr821/826 within retinoblastoma protein, leading to cell proliferation. The increase in p16 INKa expression was prevented following inhibition of β1‑integrin, or blocking the exosite within TF with AIIB2 and 10H10 antibodies, respectively. Exposure of cells to higher concentrations of TF induced disproportionate increases in p16 INKa and p21 CIP1/WAF1 expression, reduced retinoblastoma protein phosphorylation and E2F activity. Prolonged treatment of the immortalised hTERT‑HPNE cells with recombinant TF, resulted in significant downregulation of p16 INKa protein, which was partially due to reduced mRNA expression, together with increased E2F activity, and cyclin E mRNA expression. Although an increase in the methylation of the p16 INKa promoter was detected, the reduction in p16 INKa protein was concurrent with, and partly attributed to increased p14 ARF expression. TF appears early at the site of trauma, and its concentration is an ideal gauge for determining the extent of cellular damage, initiating clearance and repair. It is hypothesised that the balance of this signal is also dependent on the ability of cells to moderate the TF, and therefore on the level of damage. However, prolonged exposure of cells for example due to inflammation, leads to the dysregulation of the G1/S checkpoint by the tumour suppressors, leading to aberrant growth.

In the last couple of decades, numerous investigations have shed considerable light on how precisely factor (F)VIIa mediates the initiation of blood coagulation upon association with its cofactor, tissue factor (TF). The role of the cofactor in this process is indispensable under physiological conditions, serving as a membrane-tethering allosteric activator of FVIIa also interacting with substrates (eg, FX). Available evidence reveals the induction and manifestation of complex allostery within FVIIa when stimulated by TF, involving at least 2 connected pathways spanning the interactive interface of the FVIIa-TF complex and the functional segments of FVIIa. Carefully designed FVIIa variants demonstrate corresponding modulations of their properties and response to TF-triggered allostery and activation. In addition, antibodies can stimulate FVIIa activity in both similar and distinctly different ways compared to that employed by TF. The mechanistic insights obtained through basic biochemical investigations have been validated through select engineered FVIIa constructs which, even in vivo, demonstrate beneficial, proof-of-concept effects. Altogether, we have recently gained unprecedented knowledge about and control over FVIIa allostery, enabling us to influence FVIIa activity in advanced manners and in a desired direction. Here, we summarize our current understanding of the allosteric activation of FVIIa ending up with some prospects of future investigations., Competing Interests: Declaration of competing interests J.J.M., E.P., and O.H.O. are former employees of Novo Nordisk A/S., (Copyright © 2024 International Society on Thrombosis and Haemostasis. Published by Elsevier Inc. All rights reserved.)

Antibody-drug conjugates (ADCs) have been recognized as a promising class of cancer therapeutics. Tissue factor (TF), an initiator of the blood coagulation pathway, has been investigated regarding its relationship with cancer, and several preclinical and clinical studies have presented data on anti-TF ADCs, including tisotumab vedotin, which was approved in 2021. However, the feasibility of other payloads in the design of anti-TF ADCs is still unclear because no reports have compared payloads with different cytotoxic mechanisms. For ADCs targeting other antigens, such as Her2, optimizing the payload is also an important issue in order to improve in vivo efficacy. In this study, we prepared humanized anti-TF Ab (clone.1084) conjugated with monomethyl auristatin E (MMAE) or deruxtecan (DXd), and evaluated the efficacy in several cell line- and patient-derived xenograft models of pancreatic cancer. As a result, optimizing the drug / Ab ratio was necessary for each payload in order to prevent pharmacokinetic deterioration and maximize delivery efficiency. In addition, MMAE-conjugated anti-TF ADC showed higher antitumor effects in tumors with strong and homogeneous TF expression, while DXd-conjugated anti-TF ADC was more effective in tumors with weak and heterogeneous TF expression. Analysis of a pancreatic cancer tissue array showed weak and heterogeneous TF expression in most TF-positive specimens, indicating that the response rate to pancreatic cancer might be higher for DXd- than MMAE-conjugated anti-TF ADC. Nevertheless, our findings indicated that optimizing the ADC payloads individually in each patient could maximize the potential of ADC therapeutics., (© 2024 The Author(s). Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

Background: In healthy individuals, plasma levels of clotting proteins naturally vary within a range of 50% to 150% of their mean values. We do not know how these variations modify thrombin generation., Objectives: To assess the impact of protein level variations on simulated thrombin generation in normal and factor (F)VIII-, FIX-, or FXI-deficient blood., Methods: We used a mathematical model of flow-mediated coagulation to simulate thrombin generation with all possible combinations of clotting protein variations within the normal range and for various tissue factor levels. We selected, analyzed, and ranked combinations that enhanced thrombin generation compared with baseline., Results: Protein variations most strongly affected thrombin generation at intermediate tissue factor levels. Low tissue factor levels prevented coagulation initiation, while high tissue factor levels always triggered thrombin generation. At intermediate levels, we identified protein variations that substantially modified thrombin generation. Low-normal FV shortened lag times and increased thrombin generation, whereas high-normal FV lengthened lag times and reduced thrombin generation. With severe FVIII and FIX deficiencies, low-normal tissue factor pathway inhibitor α and antithrombin amplified the effect of low-normal FV. For moderate FVIII and FIX deficiencies, high-normal tissue factor pathway inhibitor α and antithrombin enhanced the impact of high-normal FV in reducing thrombin production. In normal and FXI-deficient blood, high-normal FVIII and FIX significantly boosted thrombin generation., Conclusion: Our mathematical model predicted how variations in clotting protein levels, within the normal range, could contribute to the variability of bleeding phenotypes observed with clotting factor deficiencies. Our study generated experimentally testable hypotheses that could aid in developing new therapies toward normal hemostasis., (© 2024 The Author(s).)

Background: E-cigarettes (ECIG) are proposed as an alternative for regular tobacco users with less dangerous effects for health. Several studies demonstrated that ECIG exert deleterious cardiovascular effects and promote platelet dependent thrombosis. However, ECIG role on Tissue Factor-dependent thrombosis is still unknown. Dysfunctional endothelial cells (ECs) are known to express Tissue Factor (TF) on their surface. Aim of the present study was to investigate whether ECIG might promote TF expression in ECs, shifting them to a pro thrombotic phenotype., Methods: Human Umbilical Vein Endothelial Cells (HUVEC) were incubated with increasing doses of ECIG (commercially available and mix of propylene glycol/vegetable glycerine/nicotine 18 mg/mL) up to 1.8 mg/mL. TF gene expression and protein levels were assessed at different time points by Real Time PCR and Western Blot, respectively. TF surface expression and activity were also measured by FACS analysis and coagulation assay. Finally, NF-kB translocation was investigated as possible mechanism of action. Potential protective effects by Rosuvastatin were also investigated., Results: ECIG significantly increased TF expression at both gene and protein levels in a time and dose dependent manner. Surface expression and procoagulant activity were increased as well. These phenomena appeared modulated by the NF-κB pathway. Rosuvastatin reduced ECIG effects on TF-mRNA., Conclusions: Although in vitro, we indicate that ECIG promote a pro thrombotic phenotype in ECs via expression of functional TF. Data of the present study permit to shed a brighter light on the still partially unresolved issue about the role of ECIG in development of cardiovascular diseases suggesting that they might represent a potential risk factor for thrombotic cardiovascular events., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: The efficacy of antibody-targeted therapy of solid cancers is limited by the lack of consistent tumour-associated antigen expression. However, tumour-associated antigens shared with non-malignant cells may still be targeted using conditionally activated-antibodies, or by chimeric antigen receptor (CAR) T cells or CAR NK cells activated either by the tumour microenvironment or following 'unlocking' via multiple antigen-recognition. In this study, we have focused on tissue factor (TF; CD142), a type I membrane protein present on a range of solid tumours as a basis for future development of conditionally-activated BiTE or CAR T cells. TF is frequently upregulated on multiple solid tumours providing a selective advantage for growth, immune evasion and metastasis, as well as contributing to the pathology of thrombosis via the extrinsic coagulation pathway., Methods: Two well-characterised anti-TF monoclonal antibodies (mAb) were cloned into expression or transposon vectors to produce single chain (scFv) BiTE for assessment as CAR and CD28-CD3-based CAR or CD3-based BiTE. The affinities of both scFv formats for TF were determined by surface plasmon resonance. Jurkat cell line-based assays were used to confirm the activity of the BiTE or CAR constructs., Results: The anti-TF mAb hATR-5 and TF8-5G9 mAb were shown to maintain their nanomolar affinities following conversion into a single chain (scFv) format and could be utilised as CD28-CD3-based CAR or CD3-based BiTE format., Conclusion: Because of the broad expression of TF on a range of solid cancers, anti-TF antibody formats provide a useful addition for the development of conditionally activated biologics for antibody and cellular-based therapy., (© 2024. The Author(s).)

Blood coagulation mediated by pig tissue factor (TF), which is expressed in pig tissues, causes an instant blood-mediated inflammatory reaction during pig-to-human xenotransplantation. Previously, we generated a soluble pig tissue factor pathway inhibitor α fusion immunoglobulin (TFPI-Ig) which inhibits pig TF activity more efficiently than human TFPI-Ig in human plasma. In this study, we generated several pig TFPI-Ig mutants and tested the efficacy of these mutants in preventing pig-to-human xenogeneic blood coagulation. Structurally important amino acid residues of pig TFPI-Ig were changed into different residues by site-directed mutagenesis. Subsequently, a retroviral vector encoding each cDNA of several pig TFPI-Ig mutants was cloned and transduced into CHO-K1 cells. After establishing stable cell lines expressing each of the pig TFPI-Ig mutants, soluble proteins were produced and purified for evaluating their inhibitory effects on pig TF-mediated blood coagulation in human plasma. The replacement of K 36 and K 257 with R 36 and H 257 , respectively, in pig TFPI-Ig more efficiently blocked pig TF activity in human plasma when compared with the wild-type pig TFPI-Ig. These results may provide additional information to understand the structure of pig TFPIα, and an improved pig TFPI-Ig variant that more efficiently blocks pig TF-mediated blood coagulation during pig-to-human xenotransplantation., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: Tofacitinib, as inhibitor of Janus kinases (JAK), interrupts the transmission of numerous pro-inflammatory cytokines involved in the pathogenesis of inflammatory bowel diseases (IBD). Therefore, tofacitinib provides a potent option to treat ulcerative colitis (UC). Besides the anti-inflammatory potential, inhibition of widespread JAKs carries the risk of side effects. Macrophages are involved in the form of different subtypes in inflammation, wound healing, and even coagulation. This study aimed to explore the balanced use of tofacitinib in M1-like as well as M2-like macrophages of healthy donors and patients with IBD., Methods: Monocytes of healthy donors and patients with chronic courses of IBD were obtained from blood samples. Macrophage colony-stimulating factor (M-CSF)-derived macrophages were treated with tofacitinib (1 µM, 5 µM, 10 µM) and polarized with either lipopolysaccharide and interferon (IFN)-γ towards M1-like-phenotype or with interleukin (IL)-4 towards M2-like-phenotype. ELISA and flow cytometry were used to evaluate cytokine levels and surface molecules., Results: Tofacitinib had a modulating effect on M1-like macrophages whereby the effect on pro-inflammatory cytokines (TNF-α, IL-6, IL-1β, IL-12, IL-23) was less pronounced than the induction of anti-inflammatory IL-10. However, during M2-like polarization tofacitinib impaired the development of the corresponding phenotype becoming evident through decreased IL-10 levels and CD206 expression in treated macrophages. In both phenotypes, tofacitinib strongly downregulated the expression of immunostimulatory molecules (CD80, CD86, CD83, CD40). Furthermore, a dose-dependent correlation between treatment with tofacitinib and expressed tissue factor was noticed., Conclusions: Tofacitinib influences both polarizations (M1/M2) and the expression of tissue factor in a dose-dependent manner., (© The Author(s) 2023. Published by Oxford University Press on behalf of Crohn’s & Colitis Foundation. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Atherosclerosis, a chronic inflammatory disease, is the most relevant cause of carotid artery stenosis. Vascular endothelial cells (ECs) play a significant role in the development of atherosclerosis. In this chronic inflammatory environment, we aimed to investigate whether PCSK9 could mitigate atherosclerosis progression by reducing tissue factor expression in ECs via in vivo and in vitro assays. In vivo, we investigated the effect of PCSK9 inhibition on preventing atherosclerotic lesion formation in ApoE -/- mice fed a western diet. The results showed that inhibiting PCSK9 could significantly downregulate the protein expression of tissue factor (TF) in ECs to reduce the area of atherosclerotic plaques. In vitro, we incubated human umbilical vein endothelial cells (HUVECs) with lipopolysaccharide (LPS). We found that LPS-induced TF elevation was suppressed by a PCSK9 inhibitor at both the mRNA and protein levels and that the TLR4/NF-κB pathway was also suppressed by a PCSK9 inhibitor. With respect to plasma samples from patients with carotid artery stenosis, we also demonstrated that the expression of TF was positively correlated with that of PCSK9. Thus, in addition to regulating lipid metabolism, the regulation of endothelial cell TF expression through the TLR4/NF-κB pathway may be a potential mechanism of PCSK9 in promoting atherosclerotic carotid stenosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: The combination of cancer and hypercoagulable states is often called Trousseau syndrome. In particular, cerebral infarction caused by Trousseau syndrome is reported to have a poor prognosis. In gynecology, there are many reports of ovarian cancer and a few of uterine cancer. Since there has been no comprehensive report of Trousseau syndrome in cervical cancer, we aimed to summarize Trousseau syndrome in cervical cancer., Methods: Cerebral infarction caused by cancer-related arterial thrombosis was defined as Trousseau syndrome. Patients with cervical cancer diagnosed at our hospital between January 2014 and December 2021 were retrospectively reviewed using the hospital's medical records., Results: A total of 1,432 patients were included in the study. Trousseau syndrome occurred in 6 patients (0.4%). The mean age of patients with Trousseau syndrome was 63 years (range: 53-78 years). Of the 6 patients who developed Trousseau's syndrome, 4 patients had it before or during initial treatment, and 2 during recurrent/relapsed disease treatment. The 4 patients who developed the syndrome before or during initial treatment had advanced disease: 1 in stage IIIC and 3 in stage IVB. In all cases, the disease was associated with progressive distant metastasis. The median survival time from the onset of Trousseau syndrome was 1 month (range: 0-6 months)., Conclusion: Cervical cancer causes Trousseau syndrome in cases of advanced disease with a short time between the onset of the syndrome and mortality., Competing Interests: No potential conflict of interest relevant to this article was reported., (© 2024. Asian Society of Gynecologic Oncology, Korean Society of Gynecologic Oncology, and Japan Society of Gynecologic Oncology.)

Aims: To detect the expression of autophagy components, p38 MAPK (p38) and phosphorylated forkhead box transcription factor O-1 (pFoxO1) in pulmonary vascular endothelial cells of chronic thromboembolic pulmonary hypertension (CTEPH) rats and to investigate the possible mechanism through which tissue factor (TF) regulates autophagy., Methods: Pulmonary artery endothelial cells (PAECs) were isolated from CTEPH (CTEPH group) and healthy rats (control group (ctrl group)) which were cocultured with TF at different time points including 12 h, 24 h, 48 h and doses including 0 nM,10 nM, 100 nM, 1µM, 10µM, 100µM and cocultured with TFPI at 48 h including 0 nM, 2.5 nM, 5 nM. The expression of forkhead box transcription factor O-1 (FoxO1), pFoxO1, p38, Beclin-1 and LC3B in PAECs was measured. Coimmunoprecipitation (co-IP) assays were used to detect the interaction between FoxO1 and LC3., Results: The protein expression of p-FoxO1/FoxO1 was significantly lower in the CTEPH groups (cocultured with TF from 0 nM to 100 µM) than in the ctrl group at 12 h, 24 h, and 48 h (P < 0.05) and was significantly lower in the CTEPH groups (cocultured with TFPI from 0 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). The protein expression of p38 in the CTEPH groups treated with 0 nM, 10 nM, 100 nM or 1 µM TF for 48 h significantly increased than ctrl groups (P < 0.05) and was significantly increased in the CTEPH groups (cocultured with TFPI concentration from 0 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). The protein expression of Beclin1 at the same concentration (cocultured with TF from 0 nM to 100 µM) was significantly lower in the CTEPH groups than ctrl groups after 24 h and 48 h (P < 0.05) and was significantly decreased in the CTEPH groups (cocultured with TFPI concentration from 2.5 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). The protein expression of LC3-II/LC3-I at the same concentration (cocultured with TF 0 nM, 1 µM, 10 µM, and 100 µM) was significantly lower in the CTEPH than in the ctrl groups after 12 h (P < 0.05) and was significantly lower in the CTEPH groups (cocultured with TFPI concentration from 0 nM to 5 nM) than in the ctrl group at 48 h (P < 0.05). There were close interactions between FoxO1 and LC3 in the control and CTEPH groups at different doses and time points., Conclusion: The autophagic activity of PAECs from CTEPH rats was disrupted. TF, FoxO1 and p38 MAPK play key roles in the autophagic activity of PAECs. TF may regulate autophagic activity through the p38 MAPK-FoxO1 pathway., (© 2024. The Author(s).)

Coagulopathy, microvascular alterations and concomitant organ dysfunctions are hallmarks of sepsis. Attempts to attenuate coagulation activation with an inhibitor of tissue factor (TF), i.e. tissue factor pathway inhibitor (TFPI), revealed no survival benefit in a heterogenous group of sepsis patients, but a potential survival benefit in patients with an international normalized ratio (INR) < 1.2. Since an increased TF/TFPI ratio determines the procoagulant activity specifically on microvascular endothelial cells in vitro, we investigated whether TF/TFPI ratio in blood is associated with INR alterations, organ dysfunctions, disseminated intravascular coagulation (DIC) and outcome in septic shock. Twenty-nine healthy controls (HC) and 89 patients with septic shock admitted to a tertiary ICU were analyzed. TF and TFPI in blood was analyzed and related to organ dysfunctions, DIC and mortality. Patients with septic shock had 1.6-fold higher levels of TF and 2.9-fold higher levels of TFPI than HC. TF/TFPI ratio was lower in septic shock compared to HC (0.003 (0.002-0.005) vs. 0.006 (0.005-0.008), p < 0.001). Non-survivors had higher TFPI levels compared to survivors (43038 (29354-54023) vs. 28041 (21675-46582) pg/ml, p = 0.011). High TFPI levels were associated with acute kidney injury, liver dysfunction, DIC and disease severity. There was a positive association between TF/TFPI ratio and troponin T (b = 0.531 (0.309-0.754), p < 0.001). A high TF/TFPI ratio is exclusively associated with myocardial injury but not with other organ dysfunctions. Systemic TFPI levels seem to reflect disease severity. These findings point towards a pathophysiologic role of TF/TFPI in sepsis-induced myocardial injury., (© 2024. The Author(s).)

Introduction: Microvesicles (MV) released by endothelial cells (EC) following injury or inflammation contain tissue factor (TF) and mediate communication with the underlying smooth muscle cells (SMC). Ser253-phosphorylated TF co-localizes with filamin A at the leading edge of migrating SMC. In this study, the influence of endothelial-derived TF-MV, on human coronary artery SMC (HCASMC) migration was examined., Methods and Results: MV derived from human coronary artery EC (HCAEC) expressing TF Wt accelerated HCASMC migration, but was lower with cytoplasmic domain-deleted TF. Furthermore, incubation with TF Asp253 -MV, or expression of TF Asp253 in HCASMC, reduced cell migration. Blocking TF-factor VIIa (TF-fVIIa) procoagulant/protease activity, or inhibiting PAR2 signaling on HCASMC, abolished the accelerated migration. Incubation with fVIIa alone increased HCASMC migration, but was significantly enhanced on supplementation with TF. Neither recombinant TF alone, factor Xa, nor PAR2-activating peptide (SLIGKV) influenced cell migration. In other experiments, HCASMC were transfected with peptides corresponding to the cytoplasmic domain of TF prior to stimulation with TF-fVIIa. Cell migration was suppressed only when the peptides were phosphorylated at position of Ser253. Expression of mutant forms of filamin A in HCASMC indicated that the enhancement of migration by TF but not by PDGF-BB, was dependent on the presence of repeat-24 within filamin A. Incubation of HCASMC with TF Wt -MV significantly reduced the levels of Smoothelin-B protein, and upregulated FAK expression., Discussion: In conclusion, Ser253-phosphorylated TF and fVIIa released as MV-cargo by EC, act in conjunction with PAR2 on SMC to promote migration and may be crucial for normal arterial homeostasis as well as, during development of vascular disease., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Featherby and Ettelaie.)

Development of thrombosis is closely associated with poor prognosis in cancer patients. Cancer patients often fulfill Virchow's triad of hyper-coagulable state, vascular endothelial injury, and venous stasis. Cancer cells aberrantly express a variety of procoagulant factors, including tissue factor and podoplanin. Chemotherapeutic agents and radiation cause vascular endothelial injury, and reduced daily activity and bed rest for chemotherapy lead to venous stasis. Due to these factors, cancer patients are at high risk of developing thrombosis. Cancer patients are also at high risk of bleeding when they have disseminated intravascular coagulation and/or chemotherapy-induced thrombocytopenia as complications. International societies, such as the American Society of Clinical Oncology and the International Initiative on Thrombosis and Cancer (ITAC), have published clinical guidelines to help physicians better manage cancer-associated thrombosis (CAT). These guidelines recommend use of low molecular weight heparin or direct oral anticoagulants for the prevention of CAT, but unfortunately use of these drugs is not approved in Japan. This gap between Japan and other countries needs to be closed., (© 2024. Japanese Society of Hematology.)

Patients with first-diagnosed atrial fibrillation (FDAF) exhibit major adverse cardiovascular events (MACEs) during follow-up. Preclinical models have demonstrated that thrombo-inflammation mediates adverse cardiac remodeling and atherothrombotic events. We have hypothesized that thrombin activity (FIIa) links coagulation with inflammation and cardiac fibrosis/dysfunction. Surrogate markers of the thrombo-inflammatory response in plasma have not been characterized in FDAF. In this prospective longitudinal study, patients presenting with FDAF ( n = 80), and 20 matched controls, were included. FIIa generation and activity in plasma were increased in the patients with early AF compared to the patients with chronic cardiovascular disease without AF (controls; p < 0.0001). This increase was accompanied by elevated biomarkers (ELISA) of platelet and endothelial activation in plasma. Pro-inflammatory peripheral immune cells (TNF-α + or IL-6 + ) that expressed FIIa-activated protease-activated receptor 1 (PAR1) (flow cytometry) circulated more frequently in patients with FDAF compared to the controls ( p < 0.0001). FIIa activity correlated with cardiac fibrosis (collagen turnover) and cardiac dysfunction (NT-pro ANP/NT-pro BNP) surrogate markers. FIIa activity in plasma was higher in patients with FDAF who experienced MACE. Signaling via FIIa might be a presumed link between the coagulation system (tissue factor-FXa/FIIa-PAR1 axis), inflammation, and pro-fibrotic pathways (thrombo-inflammation) in FDAF.

Background: Respiratory infection is associated with microvascular thrombus formation and marked elevation in cytokine levels. The role of cytokines elaborated by the pulmonary epithelium in thrombotic responses is poorly understood., Objectives: Our goal was to identify cytokines of pulmonary epithelial cell origin that enhance thrombin generation in the endothelium at concentrations equal to or less than those found in the circulation during infection., Methods: We screened multiple cytokines produced by the pulmonary epithelium for the ability to enhance toll-like receptor (TLR)-mediated endothelial thrombin generation. Effects of cytokines on tissue factor and thrombomodulin expression, cytokine selectivity for different TLRs, and prothrombotic activity of endogenous cytokines in conditioned medium from pulmonary human epithelial cells were evaluated., Results: MIP-1β, MCP-1, IL-10, IL-6, IL-1β, TNFα, IFNα, IFNβ, and IFNγ were tested for their ability to enhance TLR3-mediated thrombin generation on endothelial cells. Only interferons (IFNs) and TNFα promoted TLR3-mediated thrombin generation at levels that circulate during infection. IFNs robustly enhanced tissue factor expression when used in conjunction with TLR agonists and reduced thrombomodulin expression in the endothelium independently of TLRs. IFNα, which is typically elevated with viral infection, only synergized with TLR3 agonists mimicking viral pathogen-associated molecular patterns. In contrast, IFNγ, which is typically observed in bacterial infection, synergized more effectively with TLR4 agonists released by bacteria. Conditioned media from inflamed pulmonary epithelial cells primed the endothelium for TLR-mediated thrombin generation. Anti-IFN type I antibodies blocked this effect, indicating that endogenous IFNs prime the endothelium for TLR-mediated thrombin generation., Conclusion: IFNs elaborated by the pulmonary epithelium are necessary and sufficient to enhance TLR-mediated thrombin generation., Competing Interests: Declaration of competing interests R.F. is a founder and consultant for Platelet Diagnostics. The other authors declare no competing financial interests., (Copyright © 2023 International Society on Thrombosis and Haemostasis. Published by Elsevier Inc. All rights reserved.)

The coronary perivascular adipose tissue (cPVAT) has been associated to the burden of cardiovascular risk factors and to the underlying vessel atherosclerotic plaque severity. Although the "outside to inside" hypothesis of PVAT-derived-adipokine regulation of vessel function is currently accepted, whether the resident mesenchymal stem cells (ASCs) in PVAT have a regulatory role on the underlying vascular arterial smooth muscle cells (VSMCs) is not known. Here, we investigated the interactions between resident PVAT-ASCs and VSMCs. ASCs were obtained from PVAT overlying the left anterior descending (LAD) coronary artery of hearts removed at heart transplant operations. PVAT was obtained both from patients with non-ischemic and ischemic heart disease as the cause of heart transplant. ASCs were isolated from PVAT, phenotypically characterized by flow cytometry, functionally tested for proliferation, and differentiation. Crosstalk between ASCs and VSMCs was investigated by co-culture studies. ASCs were detected in the adventitia of the LAD-PVAT showing differentiation capacity and angiogenic potential. ASCs obtained from PVAT of non-ischemic and ischemic hearts showed different tissue factor (TF) expression levels, different VSMCs recruitment capacity through the axis ERK1/2-ETS1 signaling and different angiogenic potential. Induced upregulation of TF in ASCs isolated from ischemic PVAT rescued their angiogenic capacity in subcutaneously implanted plugs in mice, whereas silencing TF in ASCs decreased the proangiogenic capacity of non-ischemic ASCs. The results indicate for the first time a novel mechanism of regulation of VSMCs by PVAT-ASCs in angiogenesis, mediated by TF expression in ASCs. Regulation of TF in ASCs may become a therapeutic intervention to increase cardiac protection., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Venous thromboembolic events are frequent complications of Glioblastoma Multiforme (GBM) and low-grade gliomas (LGGs). The overexpression of tissue factor (TF) plays an essential role in the local hypercoagulable phenotype that underlies these complications. Our aim was to build an MRI radiomics model for the non-invasive exploration of the hypercoagulable status of LGG/GBM. Radiogenomics data from The Cancer Genome Atlas (TCGA) and REMBRANDT (Repository for molecular BRAin Neoplasia DaTa) cohorts were used. A logistic regression model (Radscore) was built in order to identify the top 20% TF-expressing tumors, considered to be at high thromboembolic risk. The most contributive MRI radiomics features from LGG/GBM linked to high TF were identified in TCGA using Least Absolute Shrinkage and Selection Operator (LASSO) regression. A logistic regression model was built, whose performance was analyzed with ROC in the TCGA/training and REMBRANDT/validation cohorts: AUC = 0.87 [CI 95 : 0.81-0.94, p < 0.0001] and AUC = 0.78 [CI 95 : 0.56-1.00, p = 0.02], respectively. In agreement with the key role of the coagulation cascade in gliomas, LGG patients with a high Radscore had lower overall and disease-free survival. The Radscore was linked to the presence of specific genomic alterations, the composition of the tumor coagulome and the tumor immune infiltrate. Our findings suggest that a non-invasive assessment of the hypercoagulable status of LGG/GBM is possible with MRI radiomics.

Extracellular vesicles (EVs) have crucial roles in hemostasis and coagulation. They sustain coagulation by exposing phosphatidylserine and initiate clotting by surface expression of tissue factor (TF) under inflammatory conditions. As their relevance as biomarkers of coagulopathy is increasingly recognized, there is a need for the sensitive and reliable detection of TF + EVs, but their flow cytometric analysis is challenging and has yielded controversial findings for TF expression on EVs in the vascular system. We investigated the effect of different fluorochrome-to-protein (F/P) ratios of anti-TF-fluorochrome conjugates on the flow cytometric detection of TF + EVs from activated monocytes, mesenchymal stem cells (MSCs), and in COVID-19 plasma. Using a FITC-labeled anti-TF antibody (clone VD8), we show that the percentage of TF + EVs declined with decreasing F/P ratios. TF was detected on 7.6%, 5.4%, and 1.1% of all EVs derived from activated monocytes at F/P ratios of 7.7:1, 6.6:1, and 5.2:1. A similar decline was observed for EVs from MSCs and for EVs in plasma, whereas the detection of TF on cells remained unaffected by different F/P ratios. We provide clear evidence that next to the antibody clone, the F/P ratio affects the flow cytometric detection of TF + EVs and should be carefully controlled., (© 2024. The Author(s).)

Background and Aims: Cancer-associated venous thromboembolism (VTE) is a frequent complication associated with high mortality in patients with cancer, particularly pancreatic cancer. While biological factors such as coagulation factors released from cancer cells may underlie the mechanisms of cancer-associated VTE, the detailed mechanisms have not been determined. Here, we aimed to determine whether extracellular vesicles carrying a glycan sialyl-Lewis a , known as carbohydrate antigen 19-9 (CA19-9), which is a clinically used serum tumor marker and selectin ligand, are a significant cause of cancer-associated VTE., Methods: Risk factors for cancer-associated VTE were determined using clinical data. EVs derived from CA19-9-deficient or overexpressing pancreatic cancer cells were characterized. The protein levels of coagulation factors on the surface of the EVs were quantified using our newly developed sensitive method., Results: Higher CA19-9 levels in the sera of patients were significantly associated with the occurrence of VTE. Using CA19-9-negative or overexpressing pancreatic cancer cells, we found that EVs derived from these cells interacted with E-selectin of endothelial cells in a CA19-9-dependent manner in cell-based assays and in vitro blood vessel models. EVs derived from cancer cells have higher tissue factor levels on their surfaces, and increased tissue factor activity is induced locally, where CA19-9-positive EVs bind to activated endothelial cells., Conclusion: These results suggest that the binding between CA19-9-positive EVs released from cancer cells and endothelial cell E-selectin explains the increased frequency of VTE in patients with pancreatic cancer., (© 2024 The Authors.)

Background: Hyperactive coagulation might cause dangerous complications such as portal vein thrombosis and pulmonary embolism after mesenchymal stem/stromal cell (MSC) therapy. Tissue factor (TF), an initiator of the extrinsic coagulation pathway, has been suggested as a predictor of this process., Methods: The expression of TF and other pro- and anticoagulant genes was analyzed in xeno- and serum-free manufactured MSCs. Furthermore, culture factors affecting its expression in MSCs were investigated. Finally, coagulation tests of fibrinogen, D-dimer, aPPTs, PTs, and TTs were measured in patient serum after umbilical cord (UC)-MSC infusions to challenge a potential connection between TF expression and MSC-induced coagulant activity.  RESULTS: Xeno- and serum-free cultured adipose tissue and UC-derived MSCs expressed the highest level of TF, followed by those from dental pulp, and the lowest expression was observed in MSCs of bone marrow origin. Environmental factors such as cell density, hypoxia, and inflammation impact TF expression, so in vitro analysis might fail to reflect their in vivo behaviors. MSCs also expressed heterogeneous levels of the coagulant factor COL1A1 and surface phosphatidylserine and anticoagulant factors TFPI and PTGIR. MSCs of diverse origins induced fibrin clots in healthy plasma that were partially suppressed by an anti-TF inhibitory monoclonal antibody. Furthermore, human umbilical vein endothelial cells exhibited coagulant activity in vitro despite their negative expression of TF and COL1A1. Patients receiving intravenous UC-MSC infusion exhibited a transient increase in D-dimer serum concentration, while this remained stable in the group with intrathecal infusion. There was no correlation between TF expression and D-dimer or other coagulation indicators., Conclusions: The study suggests that TF cannot be used as a solid biomarker to predict MSC-induced hypercoagulation. Local administration, prophylactic intervention with anticoagulation drugs, and monitoring of coagulation indicators are useful to prevent thrombogenic events in patients receiving MSCs. Trial registration NCT05292625. Registered March 23, 2022, retrospectively registered, https://www., Clinicaltrials: gov/ct2/show/NCT05292625?term=NCT05292625&draw=2&rank=1 . NCT04919135. Registered June 9, 2021, https://www., Clinicaltrials: gov/ct2/show/NCT04919135?term=NCT04919135&draw=2&rank=1 ., (© 2024. The Author(s).)

The lung can experience different oxygen concentrations, low as in hypoxia, high as under supplemental oxygen therapy, or oscillating during intermittent hypoxia as in obstructive sleep apnea or intermittent hypoxia/hyperoxia due to cyclic atelectasis in the ventilated patient. This study aimed to characterize the oxygen-condition-specific protein composition of extracellular vesicles (EVs) released from human pulmonary microvascular endothelial cells in vitro to decipher their potential role in biotrauma using quantitative proteomics with bioinformatic evaluation, transmission electron microscopy, flow cytometry, and non-activated thromboelastometry (NATEM). The release of vesicles enriched in markers CD9/CD63/CD81 was enhanced under intermittent hypoxia, strong hyperoxia and intermittent hypoxia/hyperoxia. Particles with exposed phosphatidylserine were increased under intermittent hypoxia. A small portion of vesicles were tissue factor-positive, which was enhanced under intermittent hypoxia and intermittent hypoxia/hyperoxia. EVs from treatment with intermittent hypoxia induced a significant reduction of Clotting Time in NATEM analysis compared to EVs isolated after normoxic exposure, while after intermittent hypoxia/hyperoxia, tissue factor in EVs seems to be inactive. Gene set enrichment analysis of differentially expressed genes revealed that EVs from individual oxygen conditions potentially induce different biological processes such as an inflammatory response under strong hyperoxia and intermittent hypoxia/hyperoxia and enhancement of tumor invasiveness under intermittent hypoxia.

African swine fever (ASF) is an acute and severe disease transmitted among domestic pigs and wild boars. This disease is notorious for its high mortality rate and has caused great losses to the world's pig industry in the past few years. After infection, pigs can develop symptoms such as high fever, inflammation, and acute hemorrhage, finally leading to death. African swine fever virus (ASFV) is the causal agent of ASF; it is a large DNA virus with 150-200 genes. Elucidating the functions of each gene could provide insightful information for developing prevention and control methods. Herein, to investigate the function of I267L, porcine alveolar macrophages (PAMs) infected with an I267L-deleted ASFV strain (named ∆I267L) and wild-type ASFV for 18 h and 36 h were taken for transcriptome sequencing (RNA-seq). The most distinct different gene that appeared at both 18 hpi (hours post-infection) and 36 hpi was F3; it is the key link between inflammation and coagulation cascades. KEGG analysis (Kyoto encyclopedia of genes and genomes analysis) revealed the complement and coagulation cascades were also significantly affected at 18 hpi. Genes associated with the immune response were also highly enriched with the deletion of I267L. RNA-seq results were validated through RT-qPCR. Further experiments confirmed that ASFV infection could suppress the induction of F3 through TNF-α, while I267L deletion partially impaired this suppression. These results suggest that I267L is a pathogenicity-associated gene that modulates the hemorrhages of ASF by suppressing F3 expression. This study provides new insights into the molecular mechanisms of ASFV pathogenicity and potential targets for ASFV prevention and control.

Altered properties of fibrin clots have been associated with bleeding and thrombotic disorders, including hemophilia or trauma and heart attack or stroke. Clotting factors, such as thrombin and tissue factor, or blood plasma proteins, such as fibrinogen, play critical roles in fibrin network polymerization. The concentrations and combinations of these proteins affect the structure and stability of clots, which can lead to downstream complications. The present work includes clots made from plasma and purified fibrinogen and shows how varying fibrinogen and activation factor concentrations affect the fibrin properties under both conditions. We used a combination of scanning electron microscopy, confocal microscopy, and turbidimetry to analyze clot/fiber structure and polymerization. We quantified the structural and polymerization features and found similar trends with increasing/decreasing fibrinogen and thrombin concentrations for both purified fibrinogen and plasma clots. Using our compiled results, we were able to generate multiple linear regressions that predict structural and polymerization features using various fibrinogen and clotting agent concentrations. This study provides an analysis of structural and polymerization features of clots made with purified fibrinogen or plasma at various fibrinogen and clotting agent concentrations. Our results could be utilized to aid in interpreting results, designing future experiments, or developing relevant mathematical models.

Mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into various cell types and secrete extracellular vesicles (EVs) that transport bioactive molecules and mediate intercellular communication. MSCs and MSC-derived EVs (MSC-EVs) have shown promising therapeutic effects in several diseases. However, their procoagulant activity and thrombogenic risk may limit their clinical safety. In this review, we summarize current knowledge on procoagulant molecules expressed on the surface of MSCs and MSC-EVs, such as tissue factor and phosphatidylserine. Moreover, we discuss how these molecules interact with the coagulation system and contribute to thrombus formation through different mechanisms. Additionally, various confounding factors, such as cell dose, tissue source, passage number, and culture conditions of MSCs and subpopulations of MSC-EVs, affect the expression of procoagulant molecules and procoagulant activity of MSCs and MSC-EVs. Therefore, herein, we summarize several strategies to reduce the surface procoagulant activity of MSCs and MSC-EVs, thereby aiming to improve their safety profile for clinical use., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background Aims: Mesenchymal stromal cells (MSCs) are multipotent adult cells that can be isolated from tissues including bone marrow [MSC(BM)], adipose [MSC(AT)] and umbilical cord [MSC(CT)]. Previous studies have linked expression of tissue factor (TF) on MSC surfaces to a procoagulant effect. Venous thromboembolism (VTE), immediate blood-mediated inflammatory reaction (IBMIR) and microvascular thrombosis remain a risk with intravascular MSC therapy. We examined the effect of low molecular weight heparin (LMWH) on clinical-grade MSCs using calibrated automated thrombography (CAT)., Methods: Clinical grade MSC(BM)s, MSC(AT)s and MSC(CT)s harvested at passage 4 were added to normal pooled plasma (NPP) to a final concentration of either 400 000 or 50 000 cells/mL. LMWH was added to plasma in increments of 0.1 U/mL. Thrombin generation (TG) was measured using CAT. Flow cytometry was conducted on the cells to measure MSC phenotype and TF load., Results: Presence of MSCs decreased lag time and increased peak TG. All cell lines demonstrated a dose response to LMWH, with MSC(AT) demonstrating the least thrombogenicity and most sensitivity to LMWH. TG was significantly reduced in all cell lines at doses of 0.2 U/mL LMWH and higher., Discussion: All MSC types and concentrations had a decrease in peak thrombin and TG with increasing amounts of LMWH. While this in vitro study cannot determine optimal dosing, it suggests that LMWH can be effectively used to lower the risk of VTE associated with intravascular administration of MSCs. Future in vivo work can be done to determine optimal dosing and effect on IBMIR and VTE., Competing Interests: Declaration of Competing Interest/Funding CSC has the following relationships to disclose: he has existing or previous sponsored research agreements with CBR Systems, Inc. and has served on CBR’s Scientific & Medical Advisory Board, as well as on Biostage, Inc./Harvard Apparatus Regenerative Technology, Inc.’s Scientific Advisory Board. BSG has the following relationships to disclose: Coagulex, Inc.: Sponsored Research Funding and Equity/Royalty (interest via UTHealth). UTHealth has an institutional COI for holding equity in Coagulex. JCC has funding from the Department of Defense, Aniara, and has received speaker honoraria and research funding from Grifols. SDO is supported by NINDS R21NS116302. FT and SDO have existing or previous sponsored research agreements with Biostage, Inc./Harvard Apparatus Regenerative Technology, Inc., and CBR Systems, Inc. JBS was supported by a T32 fellowship from the National Institute of General Medical Sciences of the National Institutes of Health under award number 2T32GM008792. Manufacturing of MSC(AT)s and corresponding validation was funded by FT’s and SDO’s Sponsored Research Agreements with Biostage, Inc. The manufacturing and validation of MSC(CT)s were funded by a Sponsored Research Agreements with CBR Systems, Inc. in which CSC is the primary investigator and FT and SDO are coinvestigators., (Copyright © 2023 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

Purpose: Pulmonary emboli (PE) contribute substantially to coronavirus disease 2019 (COVID-19) related mortality and morbidity. Immune cell-mediated hyperinflammation drives the procoagulant state in COVID-19 patients, resulting in immunothrombosis. To study the role of peripheral blood mononuclear cells (PBMC) in the procoagulant state of COVID-19 patients, we performed a functional bioassay and related outcomes to the occurrence of PE. Secondary aims were to relate this functional assay to plasma D-dimer levels, ventilation perfusion mismatch and TF expression on monocyte subsets., Methods: PBMC from an ICU biobank were obtained from 20 patients with a computed tomography angiograph (CTA) proven PE and compared to 15 COVID-19 controls without a proven PE. Functional procoagulant properties of PBMC were measured using a modified fibrin generation time (MC-FGT) assay. Tissue factor (TF) expression on monocyte subsets were measured by flow cytometry. Additional clinical data were obtained from patient records including end-tidal to arterial carbon dioxide gradient., Results: MC-FGT levels were highest in the samples taken closest to the PE detection, similar to the end-tidal to arterial carbon dioxide gradient (ETCO2 - PaCO2), a measurement to quantify ventilation-perfusion mismatch. In patients without proven PE, peak MC-FGT relates to an increase in end-tidal to arterial carbon dioxide gradient. We identified non-classical, CD16 positive monocytes as the subset with increased TF expression., Conclusion: We show that the procoagulant state of PBMC could aid in early detection of PE in COVID-19 ICU patients. Combined with end-tidal to ETCO2 - PaCO2 gradient, these tests could improve early detection of PE on the ICU., Competing Interests: Declaration of Competing Interest All the authors declare no conflicts of interest., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Tissue factor (TF) is the primary cellular initiator of the blood coagulation cascade. Increased levels of TF expression on circulating monocytes or on extracellular vesicles (EVs) are associated with thrombosis in a variety of diseases, including sepsis and COVID-19., Objectives: Here, we aimed to evaluate the ability of 4 commercial TF enzyme-linked immunosorbent assays (ELISAs) to measure mouse TF in cells and plasma., Methods: We used 4 commercial mouse TF ELISAs (SimpleStep, R&D Systems, MyBioSource [sandwich], and MyBioSource [competitive]). We used recombinant mouse TF (rmTF; 16-1000 pg/mL), cell lysates from a TF-expressing mouse pancreatic cancer cell line, and plasma and EVs isolated from plasma from mice injected with vehicle or bacterial lipopolysaccharide (LPS)., Results: The 2 MyBioSource kits failed to detect rmTF or TF in cell lysates. The SimpleStep and R&D kits detected rmTF in buffer or spiked into plasma in a concentration-dependent manner. These kits also detected TF in cell lysates from a mouse pancreatic cancer cell line. A higher signal was observed with the SimpleStep kit compared to the R&D kit. However, the SimpleStep and R&D kits failed to detect TF in plasma or EVs from LPS-treated mice., Conclusion: Our results indicate that some commercial ELISAs can be used to measure mouse TF levels in cell lysates but they cannot detect TF in plasma or EVs from endotoxemic mice., (© 2024 The Author(s).)

Background: Tissue factor (TF) activity is stringently regulated through processes termed encryption. Post-translational modification of TF and its interactions with various protein and lipid moieties allows for a multi-step de-encryption of TF and procoagulant activation. Membrane-associated guanylate kinase-with inverted configuration (MAGI) proteins are known to regulate the localisation and activity of a number of proteins including cell-surface receptors., Methods: The interaction of TF with MAGI1 protein was examined as a means of regulating TF activity. MDA-MB-231 cell line was used which express TF and MAGI1, and respond well to protease activated receptor (PAR)2 activation. Proximity ligation assay (PLA), co-immunoprecipitation and pull-down experiments were used to examine the interaction of TF with MAGI1-3 proteins and to investigate the influence of PAR2 activation. Furthermore, by cloning and expressing the PDZ domains from MAGI1, the TF-binding domain was identified. The ability of the recombinant PDZ domains to act as competitors for MAGI1, allowing the induction of TF procoagulant and signalling activity was then examined., Results: PLA and fluorescence microscopic analysis indicated that TF predominantly associates with MAGI1 and less with MAGI2 and MAGI3 proteins. The interaction of TF with MAGI1 was also demonstrated by both co-immunoprecipitation of TF with MAGI1, and co-immunoprecipitation of MAGI1 with TF. Moreover, activation of PAR2 resulted in reduction in the association of these two proteins. Pull-down assays using TF-cytoplasmic domain peptides indicated that the phosphorylation of Ser253 within TF prevents its association with MAGI1. Additionally, the five HA-tagged PDZ domains of MAGI1 were overexpressed separately, and the putative TF-binding domain was identified as PDZ1 domain. Expression of this PDZ domain in cells significantly augmented the TF activity measured both as thrombin-generation and also TF-mediated proliferative signalling., Conclusions: Our data indicate a stabilising interaction between TF and the PDZ-1 domain of MAGI1 and demonstrate that the activation of PAR2 disrupts this interaction. The release of TF from MAGI1 appears to be an initial step in TF de-encryption, associated with increased TF-mediated procoagulant and signalling activities. This mechanism is also likely to lead to further interactions and modifications leading to further enhancement of procoagulant activity, or the release of TF., (© 2024. The Author(s).)

Tissue factor (TF), which is a member of the cytokine receptor family, promotes coagulation and coagulation-dependent inflammation. TF also exerts protective effects through unknown mechanisms. Here, we showed that TF bound to interferon-α receptor 1 (IFNAR1) and antagonized its signaling, preventing spontaneous sterile inflammation and maintaining immune homeostasis. Structural modeling and direct binding studies revealed binding of the TF C-terminal fibronectin III domain to IFNAR1, which restricted the expression of interferon-stimulated genes (ISGs). Podocyte-specific loss of TF in mice (Pod ΔF3 ) resulted in sterile renal inflammation, characterized by JAK/STAT signaling, proinflammatory cytokine expression, disrupted immune homeostasis, and glomerulopathy. Inhibiting IFNAR1 signaling or loss of Ifnar1 expression in podocytes attenuated these effects in Pod ΔF3 mice. As a heteromer, TF and IFNAR1 were both inactive, while dissociation of the TF-IFNAR1 heteromer promoted TF activity and IFNAR1 signaling. These data suggest that the TF-IFNAR1 heteromer is a molecular switch that controls thrombo-inflammation., Competing Interests: Declaration of interests The authors J.M. and B.I. have applied for a patent related to this work., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: The clinical manifestations of acute severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) suggest a dysregulation of the host immune response that leads to inflammation, thrombosis, and organ dysfunction. It is less clear whether these dysregulated processes persist during the convalescent phase of disease or during long COVID. We sought to examine the effects of SARS-CoV-2 infection on the proportions of classical, intermediate, and nonclassical monocytes, their activation status, and their functional properties in convalescent COVID-19 patients., Methods: Peripheral blood mononuclear cells (PBMCs) from convalescent COVID-19 patients and uninfected controls were analyzed by multiparameter flow cytometry to determine relative percentages of total monocytes and monocyte subsets. The expression of activation markers and proinflammatory cytokines in response to LPS treatment were measured by flow cytometry and ELISA, respectively., Results: We found that the percentage of total monocytes was decreased in convalescent COVID-19 patients compared to uninfected controls. This was due to decreased intermediate and non-classical monocytes. Classical monocytes from convalescent COVID-19 patients demonstrated a decrease in activation markers, such as CD56, in response to stimulation with bacterial lipopolysaccharide (LPS). In addition, classical monocytes from convalescent COVID-19 patients showed decreased expression of CD142 (tissue factor), which can initiate the extrinsic coagulation cascade, in response to LPS stimulation. Finally, we found that monocytes from convalescent COVID-19 patients produced less TNF-α and IL-6 in response to LPS stimulation, than those from uninfected controls., Conclusion: SARS-CoV-2 infection exhibits a clear effect on the relative proportions of monocyte subsets, the activation status of classical monocytes, and proinflammatory cytokine production that persists during the convalescent phase of disease., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ravkov, Williams, Elgort, Barker, Planelles, Spivak, Delgado, Lin and Hanley.)

Chagas cardiomyopathy (CCC) is associated with coagulation disorders that frequently culminate in thrombotic events, contributing to increased mortality rates in this clinical condition. Considering the demonstrated effect that extracellular vesicles (EVs) have on regulating inflammatory processes, coagulation, and angiogenesis, the present study aims to characterize plasma EVs and their relationship with coagulation disorders in patients with CCC. A total of 78 patients were assessed with 46.1% (36/78) representing the CCC group, 8.9% (7/78) with cardiomyopathy unrelated to Chagas disease (CM group), and 44.8% (35/78) comprising the control group, which included individuals without cardiomyopathy and negative for T. cruzi infection. Plasma EVs concentration (EVs/mL) for each individual was evaluated by flow cytometry, along with the proportion of EVs expressing PSGL-1 (PSGL-1+ EVs), Tissue Factor (TF + EVs), and CD41a (CD41a + EVs). The ability of EVs to induce platelet aggregation was evaluated by spectrophotometry. We also evaluated other prothrombotic biomarkers, including platelet count, activated partial thromboplastin time (PTT), prothrombin time (PT), and D-dimer levels. The results revealed elevated D-dimer levels in the CCC group, accompanied by a decrease in the count of EVs per mL of plasma and a significant increase in the proportion of PSGL-1+ EVs ( P  < .05) compared to the control group. Other parameters did not exhibit significant differences between groups. The elevated levels of PSGL-1+ EVs in the CCC group may be attributed to myocardial inflammatory processes, which, upon interaction with platelet-derived P-selectin, could promote thrombus formation, as indicated by the increased D-dimer levels in this group., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Prior investigations have elucidated pathophysiological interactions involving blood coagulation and neurodegenerative diseases. These interactions pertain to age-related effects and a mild platelet antiaggregant function of exogenous α-Synuclein., Objective: Our study sought to explore whether cerebrospinal fluid (CSF) levels of tissue factor (TF), the initiator of the extrinsic pathway of hemostasis, differ between controls (CON) compared to patients with Parkinson's disease (PD) and dementia with Lewy bodies (DLB), considering that these conditions represent a spectrum of α-Synuclein pathology. We further investigated whether TF levels are associated with longitudinal progression in PD., Methods: We examined CSF levels of TF in 479 PD patients, 67 patients diagnosed with DLB, and 16 CON in order to evaluate potential continuum patterns among DLB, PD, and CON. Of the 479 PD patients, 96 carried a GBA1 variant (PD GBA1), while the 383 non-carriers were classified as PD wildtype (PD WT). We considered both longitudinal clinical data as well as CSF measurements of common neurodegenerative markers (amyloid-β 1-42, h-Tau, p-Tau, NfL, α-Synuclein). Kaplan-Meier survival and Cox regression analysis stratified by TF tertile levels was conducted., Results: Higher CSF levels of TF were associated with an older age at examination in PD and a significant later onset of postural instability in PD GBA1. TF levels were lower in male vs. female PD. DLB GBA1 exhibited the lowest TF levels, followed by PD GBA1, with CON showing the highest levels., Conclusions: TF as representative of blood hemostasis could be an interesting CSF candidate to further explore in PD and DLB.

Background: Accumulating evidence links the echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) rearrangement to venous thromboembolism (VTE) in non-small cell lung cancer (NSCLC) patients. However, the corresponding mechanisms remain unclear., Method: High-throughput sequencing analysis of H3122 human ALK-positive NSCLC cells treated with ALK inhibitor/ dimethyl sulfoxide (DMSO) was performed to identify coagulation-associated differential genes between EML4-ALK fusion protein inhibited cells and control cells. Sequentially, we confirmed its expression in NSCLC patients' tissues and in the plasma of a subcutaneous xenograft mouse model. An inferior vena cava (IVC) ligation model was used to assess clot formation potential. Additionally, pathways involved in tissue factor (TF) regulation were explored in ALK-positive cell lines H3122 and H2228. Statistical significance was determined by Student t-test and one-way ANOVA using SPSS., Results: Sequencing analysis identified a significant downregulation of TF after inhibiting EML4-ALK fusion protein activity in H3122 cells. In clinical NSCLC cases, TF expression was increased especially in ALK-positive NSCLC tissues. Meanwhile, H3122 and H2228 with high TF expression exhibited shorter plasma clotting time and higher TF activity versus ALK-negative H1299 and A549 in cell culture supernatant. Mice bearing H2228 tumor showed a higher concentration of tumor-derived TF and TF activity in plasma and the highest adjusted IVC clot weights. Limiting EML4-ALK protein phosphorylation downregulated extracellular regulated protein kinases 1/2 (ERK1/2)-activating the protein-1(AP-1) signaling pathway and thus attenuated TF expression., Conclusion: EML4-ALK fusion protein may enhance venous thrombogenicity by regulating coagulation factor TF expression. There was potential involvement of the pERK1/2-AP-1 pathway in this process., (© 2023. The Author(s).)

Tissue factor (TF) is an integral transmembrane protein associated with the extrinsic coagulation pathway. TF gene expression is regulated in response to inflammatory cytokines, bacterial lipopolysaccharides, and mechanical injuries. TF activity may be affected by phosphorylation of its cytoplasmic domain and alternative splicing. TF acts as the primary initiator of physiological hemostasis, which prevents local bleeding at the injury site. However, aberrant expression of TF, accompanied by the severity of diseases and infections under various pathological conditions, triggers multiple signaling pathways that support thrombosis, angiogenesis, inflammation, and metastasis. Protease-activated receptors (PARs) are central in the downstream signaling pathways of TF. In this study, we have reviewed the TF signaling pathways in different pathological conditions, such as wound injury, asthma, cardiovascular diseases (CVDs), viral infections, cancer and pathological angiogenesis. Angiogenic activities of TF are critical in the repair of wound injuries and aggressive behavior of tumors, which are mainly performed by the actions of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF1-α). Pro-inflammatory effects of TF have been reported in asthma, CVDs and viral infections, including COVID-19, which result in tissue hypertrophy, inflammation, and thrombosis. TF-FVII induces angiogenesis via clotting-dependent and -independent mechanisms. Clottingdependent angiogenesis is induced via the generation of thrombin and cross-linked fibrin network, which facilitate vessel infiltration and also act as a reservoir for endothelial cells (ECs) growth factors. Expression of TF in tumor cells and ECs triggers clotting-independent angiogenesis through induction of VEGF, urokinase-type plasminogen activator (uPAR), early growth response 1 (EGR1), IL8, and cysteine-rich angiogenic inducer 61 (Cyr61)., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Methotrexate (MTX) is an indispensable drug used for the treatment of many autoimmune and cancerous diseases. However, its clinical use is associated with serious side effects, such as lung fibrosis. The main objective of this study is to test the hypothesis that hydroxytyrosol (HT) can mitigate MTX-induced lung fibrosis in rats while synergizing MTX anticancer effects. Pulmonary fibrosis was induced in the rats using MTX (14 mg/kg/week, per os (p.o.)). The rats were treated with or without HT (10, 20, and 40 mg/kg/d p.o.) or dexamethasone (DEX; 0.5 mg/kg/d, intraperitoneally (i.p.)) for two weeks concomitantly with MTX. Transforming growth factor beta 1 (TGF-β1), interleukin-4 (IL-4), thromboxane A 2 (TXA 2 ), vascular endothelial growth factor (VEGF), 8-hydroxy-2-deoxy-guanosine (8-OHdG), tissue factor (TF) and fibrin were assessed using enzyme-linked immunosorbent assay (ELISA), immunofluorescence, and RT-PCR. Pulmonary fibrosis was manifested by an excessive extracellular matrix (ECM) deposition and a marked increase in TGF-β1 and IL-4 in lung tissues. Furthermore, cotreatment with HT or dexamethasone (DEX) significantly attenuated MTX-induced ECM deposition, TGF-β1, and IL-4 expression. Similarly, HT or DEX notably reduced hydroxyproline contents, TXA 2 , fibrin, and TF expression in lung tissues. Moreover, using HT or DEX downregulated the gene expression of TF. A significant decrease in lung contents of VEGF, IL-8, and 8-OHdG was also observed in HT + MTX- or DEX + MTX -treated animals in a dose-dependent manner. Collectively, the results of our study suggest that HT might represent a potential protective agent against MTX-induced pulmonary fibrosis.

Background: Cancer-associated thrombosis is a frequent complication in patients with malignancies. While factor XI (FXI)/FXIa inhibition is efficacious in preventing postoperative venous thromboembolism, its role in tumor cell-induced coagulation is less defined., Objectives: We thus aimed to provide mechanistic insights into FXI/FXIa inhibition in tumor cell-induced coagulation activation., Methods: Procoagulant activity (PCA) of 4 different tissue factor (TF) expressing tumor cell lines was analyzed by single-stage clotting and thrombin generation assay in the presence of a FXIa inhibitor, BMS-262084 (BMS), an inhibitory FXI antibody (anti-FXI), or peak and trough concentrations of rivaroxaban or tinzaparin. Further, tumor cell-induced platelet aggregation was recorded. Recombinant human TF served as positive control., Results: Although BMS and anti-FXI potently inhibited FXIa amidolytic activity, both inhibitors efficiently mitigated recombinant human TF- and tumor cell-induced fibrin clot formation and platelet aggregation only in the presence of low TF PCA. The anticoagulant effects showed an inverse correlation with the magnitude of cellular TF PCA expression. Similarly, BMS markedly interfered with tumor cell-induced thrombin generation, with the most prominent effects on peak and total thrombin. In addition, anticoagulant effects of FXIa inhibition by 10 μM BMS were in a similar range to those obtained by 600 nM rivaroxaban and 1.6 μM tinzaparin at low TF PCA levels. However, rivaroxaban and tinzaparin also exerted marked anticoagulant activity at high TF PCA levels., Conclusion: Our findings indicate that FXI/FXIa inhibition interferes with tumor cell-induced coagulation activation only at low TF PCA expression levels, a finding with potential implications for future in vivo studies., Competing Interests: Declaration of competing interests J.M., A.S., C.L., J.R., and L.B. declare no conflicts of interest relevant to the content of this article. C.C.R. has received travel support from Pfizer. M.V. declares personal fees for lectures from Bristol-Myers Squibb and travel support from Bayer, Bristol-Myers Squibb, and LEO Pharma. C.B. has received personal fees for consultancy, research support, and/or travel support from Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi Sankyo, Novartis, Pfizer, Roche, and Sanofi. F.L. has received personal fees for lectures or consultancy and/or research support from Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi Sankyo, LEO Pharma, Pfizer, Sanofi, and Viatris., (Copyright © 2023 International Society on Thrombosis and Haemostasis. Published by Elsevier Inc. All rights reserved.)