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

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

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. [ABSTRACT FROM AUTHOR]

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. Plain Language Summary: Parkinson's disease is a common age-related condition, primarily affecting older individuals. However, it shows a wide range of symptoms and clinical courses, influenced by genetic mutations, neuroinflammatory processes and lifestyle factors. Research into the disease's mechanisms is important for developing new therapies that could potentially slow its progression. Early diagnosis is also essential, as new disease-modifying therapies are most effective when started at an early stage of the disease. In this paper, we focus on a protein called tissue factor, which plays a role in both blood coagulation and neuroinflammation. Proteins involved in blood-coagulation also exhibit an increase in blood-concentration with higher age. Also, a subtle platelet antiaggregant function of exogenous α-Synuclein was found, a protein which aggregates in the brain of patients with Parkinson's disease. Additionally, higher tissue factor levels were found in plaques of proteins (amyloid-β 1-42) found in Alzheimer's disease. Thus, tissue factor could be a promising biomarker candidate for neurodegenerative diseases. We analyzed the concentration of this protein in the cerebrospinal fluid of 479 patients with Parkinson's disease, 16 control participants, and 67 patients with dementia with Lewy bodies, a sub-type of Parkinson's disease with exceptionally high levels of α-Synuclein in the brain. Our findings showed the lowest levels of tissue factor in patients with dementia with Lewy bodies, followed by those with typical Parkinson's disease, and the highest levels in controls. Additionally, older patients had higher tissue factor levels than younger patients, and levels were lower in male patients compared to female patients. Thus, measuring tissue factor levels could help in diagnosing Parkinson's disease. Further studies, especially with larger control groups, are needed to confirm these results. Additionally, exploring the connections between blood coagulation and Parkinson's disease could improve our understanding of the disease's mechanisms, potentially leading to new pharmaceutical developments. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. 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. [Display omitted] • Portal vein microthrombosis is associated with IPVD in fatal COVID-19-related hypoxia. • In thrombosed portal venules, pericytes are preponderantly infected by SARS-CoV-2. • Pericytes embedding the thrombosed portal vein radicles overexpress tissue factor. • SARS-CoV-2 induces infected pericytes to overexpress tissue factor. • Infected pericytes kindle endothelial cells to overexpress von Willebrand factor. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective: The aim of our study was to investigate salivary tissue factor (TF) activity and oxidant-antioxidant status, which is an important defense system, in saliva samples collected from patients with oral lichen planus (OLP), and to determine the relationship between the antioxidant system and TF activity in OLP. Materials and Methods: Saliva samples were collected from patients with OLP (n=20) and healthy subjects (n=13). TF activity, lipid peroxidation (LPO), nitric oxide (NO), glutathione (GSH) levels, glutathione S-transferase (GST), and superoxide dismutase (SOD) activities were measured. Results: NO levels and GST activities were increased, whereas GSH levels and SOD activities were decreased, when compared with healthy subjects in the saliva samples collected from patients with OLP. In addition, TF activity was increased in the OLP group compared with the control group. Conclusion: The results revealed that the salivary oxidant-antioxidant balance was disrupted in parallel with the increase in TF activity in patients with OLP. [ABSTRACT FROM AUTHOR]

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 K36 and K257 with R36 and H257, 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Tissue factor (TF), encoded by the F3 gene, is the main initiator of blood coagulation. The molecular epidemiology of the F3 gene and the relation to venous thromboembolism (VTE) remains to be determined. Objectives: The aim was to determine the molecular epidemiology and the importance of F3 variants for incident VTE by analysis of the population-based MDC study (Malmö Diet and Cancer), consisting of unselected middle-aged and older individuals. Methods: The exons of F3 were analyzed in a total of 28,794 individuals from the MDC cohort, and of these, 2584 (9 %) were affected by VTE during follow‐up (1991–2018). Qualifying variants used in gene-collapsing analysis were defined as loss-of-function or non-benign (PolyPhen-2) missense variants with minor allele frequency less than 0.1 %. Results: Exon sequencing of the F3 gene identified 61 different variants, 3′ UTR variants (n = 5), 5′ UTR variants (n = 9) synonymous (n = 10), in frame insertion (n = 1), splice region variants (n = 2), missense (n = 33) or loss-of-function variants (n = 1). No associations between common F3 gene variants and incident VTE were found. Seventeen rare variants were classified as qualifying and included in collapsing analysis (16 non-benign missense and 1 loss-of-function variants). The prevalence of F3 qualifying variants was 0.14 %. Seven individuals with F3 qualifying variants had VTE, while 34 individuals had no VTE. The adjusted VTE model was significant (hazard ratio = 2.1 [95 % confidence interval, 1.02–4.48], P-value = 0.045). Conclusions: Qualifying F3 gene variants are very rare, indicating a constrained gene. Rare but not common variation in the F3 gene may be involved in VTE.

Background: Anticoagulants prevent the formation of potentially fatal blood clots. Apixaban is a direct oral anticoagulant that inhibits factor (F)Xa, thereby impeding the conversion of prothrombin into thrombin and the formation of blood clots. Blood clots are held together by fibrin networks that must be broken down (fibrinolysis) to restore blood flow. Fibrinolysis is initiated when tissue plasminogen activator (tPA) converts plasminogen to plasmin, which binds to and degrades a fibrin fiber. The effects of apixaban on clot structure and lysis have been incompletely studied. Objectives: We aimed to study apixaban effects on clot structure, kinetics, and fibrinolysis using thrombin (low or high concentration) or tissue factor (TF) to activate clot formation. Methods: We used a combination of confocal and scanning electron microscopy and turbidity to analyze the structure, formation kinetics, and susceptibility to lysis when plasma was activated with low concentrations of thrombin, high concentrations of thrombin, or TF in the presence or absence of apixaban. Results: We found that the clotting activator and apixaban differentially modulated clot structure and lytic potential. Low thrombin clots with apixaban lysed quickly due to a loose network and FXa cleavage product’s cofactor with tPA; high thrombin clots lysed faster due to FXa cleavage product’s cofactor with tPA; TF generated loose clots with restricted lysis due to their activation of thrombin activatable fibrinolytic inhibitor. Conclusion: Our study elucidates the role of apixaban in fibrinolytic pathways with different clotting activators and can be used for the development of therapeutic strategies using apixaban as a cofactor in fibrinolytic pathways.

Background: Sepsis-induced disseminated intravascular coagulopathy (DIC) remains a challenging clinical entity associated with significant morbidity and mortality. Endothelial injury or activation and extracellular vesicles (EV) are postulated as important determinants of DIC. Objectives: The aim of this study was to test the discriminatory ability of E-selectin, EV, tissue factor (TF) and TF pathway inhibitor (TFPI) in sepsis-induced coagulopathy. Methods: In this prospective, single-center study, we collected plasma samples within 24 hours after sepsis diagnosis and followed these patients for 5 consecutive days. Overt DIC was determined by the International Society on Thrombosis and Haemostasis (ISTH) DIC score. Eighty-seven sepsis patients were recruited (35 with overt DIC) who presented with increased levels of EV, EV-associated TF procoagulant activity (TF-PCA), E-selectin, TF, and TFPI at admission compared with healthy subjects. Results: Only TFPI levels and TF-PCA discriminated between sepsis patients with or without DIC (area under the curve = 0.76; P = .0002). Increased TF-PCA was not sensitive in detecting sepsis-associated DIC; however, levels above 1.38 pg/mL showed high specificity in this cohort (sensitivity 27%, specificity 95%). The hazard ratio to progress to DIC over 5 days was 1.14 (95% CI, 0.64-2.07) for TF-PCA levels of 0.5 pg/mL or higher and 3.18 (95% CI, 1.74-5.79) for TFPI levels of 22.28 ng/mL or higher at admission. Conclusion: These findings highlight the pivotal roles of TF-PCA and TFPI in an early phase of sepsis-induced DIC. Only EV-associated and functionally active TF and not TF antigen levels showed a predictive potential regarding DIC. These novel results might support the improvement of diagnostic or even therapeutic strategies to mitigate the devastating consequences of DIC in septic patients.

ObjectiveRheumatoid 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.MethodsNine 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.ResultsThe 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.ConclusionThe 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.

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.

Abstract 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)

Abstract 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

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. [ABSTRACT FROM AUTHOR]

Simple Summary: Venous thromboembolic events, such as pulmonary embolism and deep venous thrombosis, are frequent and potentially severe complications of gliomas. It is currently difficult to predict their occurrence, and systematic thromboprophylaxis is not recommended because of the associated risk of bleeding. The establishment of a local hypercoagulable state constitutes the biological rationale for these complications, with a key role played by the overexpression of tissue factor (TF). We examined the possible application of radiomics analyses of tumor MRI to predict the hypercoagulable status of gliomas. Using radiogenomics data from two independent glioma cohorts, we built a model that predicts the most hypercoagulable tumors with good performance. We discuss the potential of radiomics for the prediction of vascular complications and the study of coagulation in gliomas. 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 [CI95: 0.81–0.94, p < 0.0001] and AUC = 0.78 [CI95: 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Aim: to study the role of the hemostatic system in pretem delivery in pregnant women who have had COVID-19 in the gestation period from 14 to 16 weeks.Materials and Methods. A prospective single-center observational study was conducted by enrolling 63 pregnant women with verified COVID-19 at 14–16 weeks of gestation. The main group consisted of 37 patients with preterm birth (PB), comparison group – 26 patients labour activity that occurred at least at gestational age of 37 weeks. Clinical and anamnestic data and dynamic changes in fibrinogen and D-dimer level, activity of tissue factor (TF), tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (t-PA), urokinase plasminogen activator (u-PA) were analyzed; thrombin generation assay (TGA) was performed.Results. It was found that severity of COVID-19 infection did not determine the timing of delivery that depended on patient comorbid condition. All PB observations (37 out of 63, 58.7 %) were caused by decompensated placental function manifested by acute obstetrical complications: increasing intrauterine fetal hypoxia (64.9 %) along with intrauterine growth retardation (51.4 %), severe preeclampsia (13.5 %) and premature abruption of the normally located placenta (5.0 %). In both study groups, COVID-19 experienced at 14–16 weeks of pregnancy was associated with coagulation and fibrinolytic imbalances. At the same time, at least 6 weeks post-COVID-19 infection, patients with PB had higher level of the “Peak thrombin” vs. comparison group (3050 vs. 2527 pmol/L; p = 0.0433). Also, patients with term vs. preterm delivery had TF activity decreased significantly: by 47.1% and 28.1%, respectively (p = 0.0546). Patients in preterm delivery group were characterized by fibrinolytic imbalance. At the first time point, suppressed fibrinolysis (PAI-1 level – 18.4 vs. 12.5 ng/ml in the comparison group; p = 0.0209) was concomitant with elevated level of u-PA (1.5 vs. 0.55 ng/ml in comparison group, p = 0.0015), which suggests a potential prolonged immunoinflammatory response in patients with PB. Magnitude of fibrinogen concentration and D-dimer level during post-COVID-19 follow-up study was within the reference values specific to gestational age.Conclusion. A significant increase in coagulation potential was found and verified by elevated activity of tissue factor and potential to thrombin generation in COVID-19 convalescent patients. In the case of preterm delivery, there was an imbalance in fibrinolysis system revealed by decreased blood fibrinolytic activity elevating along with increasing gestational age.

Abstract 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.

Abstract 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 .

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-Lewisa, 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.

Abstract 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.

Tissue factor (TF) is the primary initiator of blood coagulation in humans. As improper intravascular TF expression and procoagulant activity underlie numerous thrombotic disorders, there has been longstanding interest in the contribution of heritable genetic variation in F3 , the gene encoding TF, to human disease. This review seeks to comprehensively and critically synthesize small case–control studies focused on candidate single nucleotide polymorphisms (SNPs), as well as modern genome-wide association studies (GWAS) seeking to discover novel associations between variants and clinical phenotypes. Where possible, correlative laboratory studies, expression quantitative trait loci, and protein quantitative trait loci are evaluated to glean potential mechanistic insights. Most disease associations implicated in historical case–control studies have proven difficult to replicate in large GWAS. Nevertheless, SNPs linked to F3 , such as rs2022030, are associated with increased F3 mRNA expression, monocyte TF expression after endotoxin exposure, and circulating levels of the prothrombotic biomarker D-dimer, consistent with the central role of TF in the initiation of blood coagulation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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). 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. 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. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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-a and IL-6 in response to LPS stimulation, than those from uninfected controls. [ABSTRACT FROM AUTHOR]

Simple Summary: Neutrophil extracellular traps (NETs) contribute to tumor progression at different stages, such as primary growth, metastasis, angiogenesis, and cancer-associated thrombosis. The knowledge of biomolecular mechanisms of this process is crucial to developing strategies to mitigate tumor progression, mainly, metastasis. NETs promote the activation of proinflammatory pathways and trigger the epithelial-mesenchymal transition (EMT) process. In this work, we demonstrate that NETs enhance the expression of tissue factor (TF) in breast tumor cells, thus increasing the procoagulant activity. NETs also promote protease-activated receptor 2 (PAR2) signaling, leading to the expression of pro-tumor cytokines and factors associated with EMT. These phenomena are supported by in silico gene correlation analysis of TF/PAR2 and pro-tumor genes analyzed in samples from breast cancer patients. Our results suggest that the TF/PAR2 signaling axis contributes to the pro-cancer effects of NETs in human breast cancer cells. Neutrophil extracellular traps (NETs) have been implicated in several hallmarks of cancer. Among the protumor effects, NETs promote epithelial-mesenchymal transition (EMT) in different cancer models. EMT has been linked to an enhanced expression of the clotting-initiating protein, tissue factor (TF), thus favoring the metastatic potential. TF may also exert protumor effects by facilitating the activation of protease-activated receptor 2 (PAR2). Herein, we evaluated whether NETs could induce TF expression in breast cancer cells and further promote procoagulant and intracellular signaling effects via the TF/PAR2 axis. T-47D and MCF7 cell lines were treated with isolated NETs, and samples were obtained for real-time PCR, flow cytometry, Western blotting, and plasma coagulation assays. In silico analyses were performed employing RNA-seq data from breast cancer patients deposited in The Cancer Genome Atlas (TCGA) database. A positive correlation was observed between neutrophil/NETs gene signatures and TF gene expression. Neutrophils/NETs gene signatures and PAR2 gene expression also showed a significant positive correlation in the bioinformatics model. In vitro analysis showed that treatment with NETs upregulated TF gene and protein expression in breast cancer cell lines. The inhibition of ERK/JNK reduced the TF gene expression induced by NETs. Remarkably, the pharmacological or genetic inhibition of the TF/PAR2 signaling axis attenuated the NETs-induced expression of several protumor genes. Also, treatment of NETs with a neutrophil elastase inhibitor reduced the expression of metastasis-related genes. Our results suggest that the TF/PAR2 signaling axis contributes to the pro-cancer effects of NETs in human breast cancer cells. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

IntroductionMicrovesicles (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 ResultsMV derived from human coronary artery EC (HCAEC) expressing TFWt accelerated HCASMC migration, but was lower with cytoplasmic domain-deleted TF. Furthermore, incubation with TFAsp253-MV, or expression of TFAsp253 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 TFWt-MV significantly reduced the levels of Smoothelin-B protein, and upregulated FAK expression.DiscussionIn 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.

Lusine Hazarapetyan,1,2 Parounak H Zelveian,2 Svetlana Grigoryan1,2 1Department of Cardiology, Yerevan State Medical University Named After M. Heratsi, Yerevan, Armenia; 2Scientific Research Institute of Cardiology Named After L Hovhannisyan, Yerevan, ArmeniaCorrespondence: Svetlana Grigoryan, Department of Cardiology, Yerevan State Medical University, 5 P. Sevak Street, Yerevan, 0044, Armenia, Tel +374-91-415 − 123, Email s.grigoryan@interdiagnostika.comIntroduction: Atrial fibrillation (AF) is associated with elevated levels of clotting factors such as tissue factor (TF) and factor XII (FXII). Various inflammation markers, such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF- α), and high-sensitive C-reactive protein (hs-CRP), have also been associated with AF. This study explores the relationship between inflammation markers and coagulation activity, including their impact on heart structural changes in these patients.Methods: We observed 283 patients with nonvalvular AF who underwent a complete examination at admission, but only 183 patients have successful cardioversion. As a control group, similar patients without AF were examined. The markers of the coagulation and inflammation were studied by ELISA on the analyzer “Stat Fax 303 Plus”. Studies were conducted using l statistical package SPSS 13.0.Results: It was revealed that patients with AF had significantly higher levels of hs-CRP, IL-6, and TNF-α and had elevated levels of TF and FXII compared with control group. The moderate correlations were observed between IL-6 and left atrial diameter (LAD), IL-6 and LA stiffness, hs-CRP and left atrial volume (LAV), TF and LAV.Conclusion: We have demonstrated that patients with AF have the relationship between elevated levels of inflammatory markers and coagulation activity, which contributes to structural atrial remodeling.Keywords: atrial fibrillation, hs-C reactive protein, interleukin-6, tissue factor, factor XII

The number of mesenchymal stromal/stem cell (MSC) therapeutics and types of clinical applications have greatly diversified during the past decade, including rapid growth of poorly regulated "Stem Cell Clinics" offering diverse "Unproven Stem Cell Interventions." This product diversification necessitates a critical evaluation of the reliance on the 2006 MSC minimal criteria to not only define MSC identity but characterize MSC suitability for intravascular administration. While high-quality MSC therapeutics have been safely administered intravascularly in well-controlled clinical trials, repeated case reports of mild-to-more-severe adverse events have been reported. These are most commonly related to thromboembolic complications upon infusion of highly procoagulant tissue factor (TF/CD142)-expressing MSC products. As TF/CD142 expression varies widely depending on the source and manufacturing process of the MSC product, additional clinical cell product characterization and guidelines are needed to ensure the safe use of MSC products. To minimize risk to patients receiving MSC therapy, we here propose to supplement the minimal criteria used for characterization of MSCs, to include criteria that assess the suitability of MSC products for intravascular use. If cell products are intended for intravascular delivery, which is true for half of all clinical applications involving MSCs, the effects of MSC on coagulation and hemocompatibility should be assessed and expression of TF/CD142 should be included as a phenotypic safety marker. This adjunct criterion will ensure both the identity of the MSCs as well as the safety of the MSCs has been vetted prior to intravascular delivery of MSC products.

IntroductionThe 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.MethodsPeripheral 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.ResultsWe 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.ConclusionSARS-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.

Objective: IL-1b is a leaderless cytokine with poorly known secretory mechanisms that is barely detectable in serum of patients, including those with an IL-1b-mediated disease such as systemic juvenile idiopathic arthritis (sJIA). Leukocyte microvesicles (MVs) may be a mechanism of IL-1b secretion. The first objective of our study was to characterize IL-1b-positive MVs obtained from macrophage cell culture supernatants and to investigate their biological functions in vitro and in vivo. The second objective was to detect circulating IL-1b-positive MVs in JIA patients. Methods: MVs were purified by serial centrifugations from PBMCs, or THP-1 differentiated into macrophages, then stimulated with LPS ± ATP. MV content was analyzed for the presence of IL-1b, NLRP3 inflammasome, caspase-1, P2X7 receptor, and tissue factor (TF) using ELISA, Western blot, or flow cytometry. MV biological properties were studied in vitro by measuring VCAM-1, ICAM-1, and Eselectin expression after HUVEC co-culture and factor-Xa generation test was realized. In vivo, MVs’ ability to recruit leukocytes in a murine model of peritonitis was evaluated. Plasmatic IL-1b-positive MVs were studied ex vivo in 10 active JIA patients using flow cytometry. Results: THP-1-derived macrophages stimulated with LPS and ATP released MVs, which contained NLRP3, caspase-1, and the 33-kDa precursor and 17-kDa mature forms of IL-1b and bioactive TF. IL-1b-positive MVs expressed P2X7 receptor and released soluble IL-1b in response to ATP stimulation in vitro. In mice, MVs induced a leukocyte peritoneal infiltrate, which was reduced by treatment with the IL-1 receptor antagonist. Finally, IL-1b-positive MVs were detectable in plasma from 10 active JIA patients. Conclusion: MVs shed from activated macrophages contain IL-1b, NLRP3 inflammasome components, and TF, and constitute thrombo-inflammatory vectors that can be detected in the plasma from active JIA patients. [ABSTRACT FROM AUTHOR]