Expression of tissue factor in rabbit pulmonary artery in an acute pulmonary embolism model

Prevalence and Risk Factors of Pulmonary Embolism in COPD Patients Complicated with Secondary Polycythemia

Purpose

This study aimed to establish the prevalence of pulmonary embolism (PE) in chronic obstructive pulmonary disease (COPD) patients with secondary polycythemia (SP) and explore the risk factors for PE in COPD patients with SP.

Patients and Methods

We analyzed the prevalence of PE among COPD patients with SP who were hospitalized at Qinghai Provincial People's Hospital between January 2015 and December 2020. From January 2021 to January 2024, we enrolled patients into three groups (COPD+SP+PE, COPD+SP, and control) and performed laboratory measurements, biomarkers, echocardiography, and pulmonary function tests. Patients in the COPD+SP group received clinical treatment, and biomarkers were measured again seven days after treatment.

Results

The prevalence of PE in patients with COPD SP was 5.21%. We found that COPD+SP+PE group had significantly higher levels of erythrocyte distribution width (RDW), platelet volume distribution width (PDW), mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), monocyte to large platelet ratio (MLPR), 5-hydroxytryptamine (5-HT), activated protein C (APC), urokinase-type plasminogen activator (u-PA), thrombomodulin (TM), interleukin-38 (IL-38), tissue factor (TF), and fractalkine (FKN) in contrast to COPD+SP group. Biomarkers, such as FKN, β-thromboglobulin (β-TG), APC, u-PA, TM, TF, and IL-38, were risk factors for COPD patients with SP who are complicated by PE. Clinical treatment significantly reduced the levels of β-TG, IL-38, APC, endothelin-1 (ET-1), u-PA, FKN, TM, 5-HT, and neutrophil extracellular traps (NETs) in patients with COPD+SP.

Conclusion

PE incidence was significantly higher in patients with COPD and SP. In COPD patients with SP, routine joint detection of blood and cardiac markers, blood gas analysis, and pulmonary function tests can help to identify patients with PE. APC, u-PA, TF, FKN, TM, and IL-38 are risk factors for PE in patients with COPD and SP, and clinical treatment can effectively reduce this risk.

Decreased Pulmonary Artery Bifurcation Angle: A Novel Imaging Criterion for the Diagnosis of Chronic Pulmonary Thromboembolism

Background

Chronic pulmonary thromboembolism (CTEPH) is an unusual complication of acute pulmonary embolism (PE), which is now considered to be treatable. In modern multi-detector scanners, a detailed evaluation of pulmonary artery geometry is currently possible. This study aimed to evaluate the changes in pulmonary artery bifurcation angle (PABA) in the follow-up computed tomography angiography (CTA) of patients with acute PE.

Methods

In this cross-sectional study, the records of two tertiary-level academic hospitals were gathered from 2012 to 2019. Pulmonary artery (PA) bifurcation angle and diameter were measured. Chi square test, independent samples t test, Mann-Whitney, and Pearson's tests were employed to compare data. To evaluate the cut-off point, we utilized receiver operating characteristic (ROC) curve analysis. The accuracy, sensitivity, and specificity of pulmonary artery bifurcation angle changes were calculated. A P value <0.05 was considered to be significant.

Results

Forty-six patients were included in the study. No significant differences were found between patients with and without CTEPH, and PABA in the dimeters of PA trunk, right PA, and left PA in the first CTA images (P values of 0.151, 0.142, 0.891, and 0.483, respectively), while in the secondary CTA, the mean PABA was significantly smaller in patients with CTEPH (P=0.011). In the receiver operating characteristic (ROC) analysis, delta angle revealed an area under the curve of 0.745 and an optimal cutoff of 0, leading to a sensitivity of 64%, specificity of 87%, and accuracy of 76% for diagnosing CTEPH.

Conclusion

We showed a significant decrease in PABA in patients developing CTEPH. This parameter can be easily measured in lung CTA.

Ruscogenin alleviates deep venous thrombosis and pulmonary embolism induced by inferior vena cava stenosis inhibiting MEK/ERK/Egr-1/TF signaling pathway in mice

BACKGROUND

Ruscogenin (RUS) has anti-inflammatory and antithrombotic effects, while its potential effects on deep venous thrombosis (DVT) and pulmonary embolism (PE) remain unclear.

OBJECTIVE

We aimed to elucidate the effects of RUS on DVT and PE induced by the inferior vena cava stenosis (IVCS) model and investigate the underlying mechanism.

METHODS

Male C57/BL6 mice were used to explore whether IVCS model could be complicated with deep venous thrombosis and pulmonary embolism. Then, Effects of RUS on DVT and PE related inflammatory factors and coagulation were examined using H&E staining, ELISA, and real-time PCR. Western blot analysis was used to examine the effects of RUS on MEK/ERK/Egr-1/TF signaling pathway in PE.

RESULTS

IVCS model induced DVT and complied with PE 48 h after surgery. Administration of RUS (0.01, 0.1, 1 mg/kg) inhibited DVT, decreased biomarker D-Dimer, cardiac troponin I, N-Terminal probrain natriuretic peptide in plasma to ameliorate PE induced by IVCS model. Meanwhile, RUS reduced tissue factor and fibrinogen content of lung tissue, inhibited P-selectin and C-reactive protein activity in plasma, and suppressed the expressions of interleukin-6 and interleukin-1β in mice. Furthermore, RUS suppressed the phosphorylation of ERK1/2 and MEK1/2, decreasing the expressions of Egr-1 and TF in the lung.

CONCLUSION

IVCS model contributed to the development of DVT and PE in mice and was associated with increased inflammation. RUS showed therapeutic effects by inhibiting inflammation as well as suppressing the activation of MEK/ERK/Egr-1/TF signaling pathway.

The Levels of TNF-α, Tissue Factor, and Coagulation Function in Rats with Pulmonary Hypertension and the Intervention Effect of Sildenafil Encapsulated by Targeted Nanocarriers

Pulmonary hypertension (PAH) is a proliferative disease of pulmonary blood vessels, but the pathogenesis of pulmonary hypertension is still unclear. This article explores the role of tumor necrosis factor-α (TNF-α), tissue factor (TF), and coagulation function (CF) in the pathogenesis of PAH. PAH is often accompanied by vascular intima injury and muscular arterial media thickening. Coupled with the wide application of nanotargeted drugs in recent years, a targeted nanocarrier encapsulating sildenafil was prepared in this study. The particle size, PDI, zeta potential, drug loading, and encapsulation efficiency were $194.32\pm 17.31\text{nm}$ , $0.28\pm 0.02$ , $-6.34\pm 0.33$ , 24.61%, and 70.52%. The monocrotaline PAH rat model was constructed, and it was found that the levels of TNF-α, TF, and CF in the peripheral blood of PAH rats were abnormally increased. 30 PAH rats were randomly divided into 5 groups and injected with saline (NS group), sildenafil (sildenafil group), target the nanoempty carrier (TNC-E group), ordinary nanocarrier encapsulated sildenafil (CNC-sildenafil group), and targeted nanocarrier encapsulate sildenafil (TNC-sildenafil group). Compared with the NS group, the mean pulmonary artery pressure in the TNC-sildenafil group was lower ( $P<0.05$ ). Compared with the normal rat group, the pulmonary small blood vessel media thickness, TNF-α level, TF level, and the area of myocardial cells were increased in the NS group, sildenafil group, TNC-E group, and CNC-sildenafil group ( $P<0.05$ ). Compared with the NS group, the pulmonary small blood vessel media thickness, myocardial cell area, and the levels of TNF-α and TF in the TNC-sildenafil group were reduced ( $P<0.05$ ). Targeting nanocarrier encapsulation of sildenafil can obviously reduce the average pulmonary artery pressure in rats with pulmonary hypertension, improve pulmonary vascular media proliferation and myocardial hypertrophy, and restore the levels of TNF-α, TF, and CF to a normal state.

Rodent models of pulmonary embolism and chronic thromboembolic pulmonary hypertension

Pulmonary embolism (PE) is the third most prevalent cardiovascular disease. It is associated with high in-hospital mortality and the development of acute and chronic complications. New approaches aimed at improving the prognosis of patients with PE are largely dependent on reliable animal models. Mice, rats, hamsters, and rabbits, are currently most commonly used for PE modeling because of their ethical acceptability and economic feasibility. This article provides an overview of the main approaches to PE modeling, and the advantages and disadvantages of each method. Special attention is paid to experimental endpoints, including morphological, functional, and molecular endpoints. All approaches to PE modeling can be broadly divided into three main groups: 1) induction of thromboembolism, either by thrombus formation in vivo or by injection of in vitro prepared blood clots; 2) introduction of particles of non-thrombotic origin; and 3) surgical procedures. The choice of a specific model and animal species is determined based on the objectives of the study. Rodent models of chronic thromboembolic pulmonary hypertension (CTEPH), which is the most devastating complication of PE, are also described. CTEPH models are especially challenging because of insufficient knowledge about the pathogenesis and high fibrinolytic activity of rodent plasma. The CTEPH model should demonstrate a persistent increase in pulmonary artery pressure and stable reduction of the vascular bed due to recurrent embolism. Based on the analysis of available evidence, one might conclude that currently, there is no single optimal method for modeling PE and CTEPH.

Changes of fibrinolytic system in thrombolytic resuscitation of pulmonary thromboembolism-induced cardiac arrest model

The objective of this study is to explore the changes in the coagulation and fibrinolysis system in an animal model with pulmonary embolism after cardiopulmonary bypass and to provide a theoretical basis for clinical practice. An animal model of cardiac arrest due to pulmonary embolism was established for venous thrombus (10-15 mL) in the left external jugular vein of 21 pigs. Computed tomography (CT) pulmonary arteriography was performed after the recovery of the underlying state, cardiac arrest state and spontaneous circulation, and then thrombolysis and cardiopulmonary resuscitation (recombinant tissue plasminogen activator [t-PA] 50 mg) were performed immediately. The changes of tissue factor (TF), tissue factor pathway inhibitor (TFPI), t-PA and plasminogen activator inhibitor-1 (PAI-1) in the blood were detected by ELISA. The blood samples were collected immediately, 1, 2, 4 and 6 hours after the recovery of spontaneous circulation. Data from animals that were successfully resuscitated at different time points were compared using a repeated measures one-way analysis of variance. Seventeen pigs had cardiac arrest after 10 to 15 mL of thrombus injection, and the other four had cardiac arrest after 5 to 8 mL of additional thrombus. Nine pigs survived 6 hours of cardiopulmonary resuscitation. CT pulmonary angiogram showed pulmonary artery obstruction. TF levels were increased compared with basal status, but there was no statistical difference (P > .05). TFPI levels were higher at 1, 2, 4 and 6 hours after recovery of spontaneous circulation compared with basal state (P < .05); t-PA levels were higher at cardiac arrest, and immediately after recovery of spontaneous circulation compared with basal state. There was a statistical difference in PAI-1 level at 1, 2, 4 and 6 hours after recovery of spontaneous circulation (P < .05). There was no statistical difference in PAI-1 level at each stage compared with basal state (P > .05). TFPI has a certain influence on the coagulation and thrombosis regulation of the body, and the increase in fibrinolytic activity has a positive promoting effect on the thrombolysis. It provided the theoretical basis of clinical treatment of thrombotic diseases.

Risk Assessment in Chinese Hospitalized Patients Comparing the Padua and Caprini Scoring Algorithms

The current venous thromboembolism (VTE) guidelines recommend all patients to be assessed for the risk of VTE using risk assessment models (RAMs). The study was to evaluate the performance of the Caprini and Padua RAMs among Chinese hospitalized patients. We reviewed data from 189 patients with deep venous thrombosis (DVT) and 201 non-DVT patients. Deep venous thrombosis risk factors were obtained from all patients. The sensitivity and specificity of the Caprini and Padua scores for all patients were calculated. The receiver operating curve (ROC) and the area under the ROC curve (AUC) were used to evaluate the performance of each score. We documented that age, acute infection, prothrombin time (PT), D-dimer, erythrocyte sedimentation rate, blood platelets, and anticoagulation were significantly associated with the occurrence of DVT (P < .05). These results were true for all medical and surgical patients group (G1), as well as the analysis of medical versus surgical patients (G2). Finally, analysis of the scores in patients with and without cancer was also done (G3). The Caprini has a higher sensitivity but a lower specificity than the Padua (P < .05). Caprini has a better predictive ability for the first 2 groups (P < .05). We found Caprini and Padua scores have a similar predictive value for patients with cancer (P > .05), while Caprini has a higher predictive ability for no cancer patients in G3 than Padua (P < .05). For Chinese hospitalized patients, Caprini has a higher sensitivity but a lower specificity than Padua. Overall, Caprini RAM has a better predictive ability than Padua RAM.

Recent Progress in Research on the Pathogenesis of Pulmonary Thromboembolism: An Old Story with New Perspectives

Pulmonary thromboembolism (PTE) is part of a larger clinicopathological entity, venous thromboembolism. It is also a complex, multifactorial disorder divided into four major disease processes including venous thrombosis, thrombus in transit, acute pulmonary embolism, and pulmonary circulation reconstruction. Even when treated, some patients develop chronic thromboembolic pulmonary hypertension. PTE is also a common fatal type of pulmonary vascular disease worldwide, but earlier studies primarily focused on the pathological changes in the blood component of the disease. With contemporary advances in molecular and cellular biology, people are becoming increasingly aware of coagulation pathways, the function of vascular smooth muscle cells, microparticles, and the inflammatory pathways that play key roles in PTE. Combined hypoxia and immune research has revealed that PTE should be regarded as a class of complex diseases caused by multiple factors involving the vascular microenvironment and vascular cell dysfunction.

The role of mononuclear cell tissue factor and inflammatory cytokines in patients with chronic thromboembolic pulmonary hypertension

Thrombosis and inflammation are two major factors underlying chronic thromboembolic pulmonary hypertension (CTEPH). Tissue factor (TF), C-reactive protein (CRP), tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1) may play critical roles in the process of CTEPH thrombosis and pulmonary vascular remodeling. Ten patients with a confirmed diagnosis of CTEPH, 20 patients with acute pulmonary thromboembolism and 15 patients with other types of pulmonary hypertension were enrolled in this study, along with 20 healthy subjects as the control group. The immunoturbidimetric method was used to determine the plasma content of CRP. The plasma levels of TNF-α, MCP-1, and TF antigen were measured by an enzyme-linked immunosorbent assay, and TF activity was measured by the chromogenic substrate method. Percoll density gradient centrifugation was used to separate peripheral blood mononuclear cells from plasma. The level of monocyte TF mRNA was examined by reverse transcriptase-polymerase chain reaction. The correlations between all indices described above were analyzed. In CTEPH patients, the expression of CRP, TNF-α, and MCP-1 was significantly higher than that in controls (P < 0.05). The levels of TF activity, TF antigen, and TF mRNA in monocyte cells were increased in CTEPH patients when compared with control subjects, but only the TF antigen and TF mRNA levels were significantly different (P < 0.05). In CTEPH patients, levels of CRP, MCP-1, and TNF-α significantly correlated with the level of TF antigen in plasma. TF gene expression was increased in patients with CTEPH, suggesting that blood-borne TF mainly comes from mononuclear cells. TF expression significantly correlated with levels of CRP, TNF-α and MCP-1. These factors may play an important role in the development of CTEPH via the inflammation–coagulation–thrombosis cycle.

Expression of tissue factor and forkhead box transcription factor O-1 in a rat model for chronic thromboembolic pulmonary hypertension

Few reports have examined tissue factor (TF) and forkhead box transcription factor O-1 (FoxO1) expression in chronic thromboembolic pulmonary hypertension (CTEPH) animal models. To investigate the role of TF and FoxO1 and their interactions during CTEPH pathogenesis in a rat model. Autologous blood clots were repeatedly injected into the pulmonary arteries through right jugular vein to induce a rat model of CTEPH. Hemodynamic parameters, histopathology, and TF and FoxO1expression levels were detected. The mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance and vessel wall area/total area (WA/TA) ratio in the experiment group increased significantly than sham group (P < 0.05). The cardiac output in the 1-, 2-, and 4-week groups decreased significantly (P < 0.05) when compared to sham group. TF mRNA expression levels in the experiment group increased significantly than sham group (P < 0.05). FoxO1 mRNA and protein expression levels were lower in the experiment group than sham group (P < 0.05). The mPAP had a positive correlation with WA/TA ratio (r = 0.45, P = 0.01). TF mRNA expression had a positive correlation with WA/TA ratio (r = 0.374, P = 0.035) and a positive correlation with mPAP (r = 0.48, P= 0.005). FoxO1 mRNA expression had a negative correlation trend with the WA/TA ratio (r = -0.297, P = 0.099) and a negative correlation trend with mPAP (r = -0.34, P = 0.057). TF mRNA expression had a negative correlation with FoxO1 mRNA expression (r = -0.62, P < 0.001). A rat model of CTEPH can be successfully established by the injection of autologous blood clots into the pulmonary artery. TF and FoxO1 may play a key role in vascular remodeling during CTEPH pathogenesis.

The role of tissue factor and autophagy in pulmonary vascular remodeling in a rat model for chronic thromboembolic pulmonary hypertension

Background

Few reports have examined tissue factor (TF) and autophagy expression in chronic pulmonary thromboembolic hypertension (CTEPH) animal models. Objectives: To investigate the role of tissue factor (TF), autophagy and their interactions during chronic thromboembolic pulmonary hypertension (CTEPH) pathogenesis in a rat model.

Methods

Autologous blood clots were repeatedly injected into the left jugular vein of rats with injecting endogenous fibrinolysis inhibitor tranexamic acid (TXA). Mean pulmonary arterial pressure (mPAP), histopathology and TF, Beclin-1 and microtubule-associated protein 1 light chain (LC3) expression levels were detected.

Results

The mPAP and vessel wall area/total area (WA/TA) ratio in the experiment group increased significantly (P < 0.05). TF mRNA and protein expression levels in the experiment group increased significantly (P < 0.05). Beclin-1 and LC3B mRNA and protein expression levels were lower in the experiment group (P < 0.05). The mPAP had a positive correlation with WA/TA ratio (r = 0.955, P < 0.05). Beclin-1 and LC3B protein expression had a negative correlation with the WA/TA ratio (r = -0.963, P < 0.05, r = -0.965, P < 0.05, respectively). TF protein expression had a negative correlation with both Beclin-1 and LC3B protein expression (r = -0.995, P <0.05, r = -0972, P < 0.05, respectively).

Conclusions

A rat model of CTEPH can be established by repeatedly introducing autologous blood clots into the pulmonary artery with injecting TXA. TF and autophagy may play a key role during CTEPH pathogenesis, especially in vascular remodeling.