thromboplastin and Hypertension--Pulmonary

Tissue factor is the primary initiator of coagulation cascade and plays an essential role in haemostasis and thrombosis. In addition, tissue factor and coagulation proteases contribute to many cellular responses via activation of protease activated receptors. The heart is an organ with high levels of constitutive tissue factor expression. This review focuses on the role of tissue factor, coagulation proteases and protease activated receptors in heart haemostasis and the pathological heart remodelling associated with myocardial infarction, viral myocarditis and hypertension.

Topics: Animals; Blood Coagulation Factors; Fibrosis; Heart Valve Diseases; Hemostasis; Humans; Hypertension; Hypertension, Pulmonary; Hypertrophy; Models, Cardiovascular; Myocardial Infarction; Myocarditis; Myocytes, Cardiac; Receptors, Proteinase-Activated; Renin-Angiotensin System; Thromboplastin; Ventricular Remodeling

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare clinicopathological entity causing severe pulmonary hypertension (PH). Its histological features include widespread tumor emboli of the small arteries and arterioles of the lung, associated with thrombus formation and fibrocellular and fibromuscular intimal proliferation. Although PTTM has drawn increased attention as a fatal complication of gastric carcinoma (GC), comprehensive studies are still lacking. In order to clarify clinical and pathological features of GC-induced PTTM, recent autopsy cases were analyzed with a review of the literature. Of 36 autopsy cases with GC, 6 (16.7%) were affected by PTTM. Four were male and 2 female, with a mean age of 72.7 years. Three patients presented with PTTM-related clinical manifestations and died of PTTM. They showed clear morphological evidence of PH. The other 3 patients had PTTM as an incidental finding irrespective of clinical manifestations or PH. No patient was diagnosed antemortem as PTTM. All PTTM cases were associated with advanced GC, with a histology of adenocarcinoma of poorly differentiated type (n=4) or signet-ring cell type (n=2). Expression of tissue factor and vascular endothelial growth factor was confirmed immunohistochemically in tumor cells in all cases. The results were all in line with previous studies. In addition, the current study revealed vascular lesions characteristic of PTTM morphology to be present exclusively in the lung. In conclusion, our study shows a 16.7% incidence of PTTM in GC patients, with half of them developing PH and dying of PTTM, confirming a clinical significance as a non-negligible lethal complication of GC. In addition to many known clinicopathological characteristics of PTTM, the current study pointed to some PTTM issues requiring clarification, including the pathogenesis of the exclusive pulmonary distribution of vascular lesions of PTTM. Since details remain to be elucidated, interdisciplinary research is a high priority with a close collaboration between pathologists and clinicians in order to overcome this lethal condition.

Topics: Adenocarcinoma; Aged; Aged, 80 and over; Autopsy; Carcinoma, Signet Ring Cell; Cell Differentiation; Female; Humans; Hypertension, Pulmonary; Immunohistochemistry; Lung Neoplasms; Male; Middle Aged; Neoplastic Cells, Circulating; Stomach Neoplasms; Thromboplastin; Thrombotic Microangiopathies; Vascular Endothelial Growth Factor A

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-

Topics: Animals; Blood Coagulation; Disease Models, Animal; Drug Carriers; Hypertension, Pulmonary; Monocrotaline; Nanoparticles; Pulmonary Artery; Rats; Sildenafil Citrate; Thromboplastin; Tumor Necrosis Factor-alpha

In situ thrombus formation is one of the major pathological features of pulmonary hypertension (PH). The mechanism of in situ thrombosis has not been clearly identified. Fibrinogen-like protein 2 (FGL2) prothrombinase is an immune coagulant that can cleave prothrombin to thrombin, which then converts fibrinogen into fibrin. This mechanism triggers in situ thrombus formation directly, bypassing both the intrinsic and extrinsic coagulation pathways. FGL2 prothrombinase is mainly expressed in endothelial cells and mediates multiple pathological processes. This implies that it may also play a role in PH. In this study, we examined the expression of FGL2 in idiopathic pulmonary arterial hypertension (IPAH) patients, and in monocrotaline-induced rat and hypoxia-induced mouse PH models.

Topics: Aged; Animals; Apoptosis; Disease Models, Animal; Down-Regulation; Endothelial Cells; Endothelium, Vascular; Fibrin; Fibrinogen; Humans; Hypertension, Pulmonary; Male; Mice, Inbred C57BL; Mice, Knockout; Middle Aged; Rats; Rats, Sprague-Dawley; Signal Transduction; Thromboplastin; Up-Regulation

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.

Topics: C-Reactive Protein; Case-Control Studies; Chemokine CCL2; Chronic Disease; Cytokines; Humans; Hypertension, Pulmonary; Monocytes; Pulmonary Embolism; RNA, Messenger; Thromboplastin; Tumor Necrosis Factor-alpha

The aetiology of chronic thromboembolic pulmonary hypertension (CTEPH) is not clearly understood. In some patients, the disease is preceded by acute pulmonary embolism (APE), and is characterised by intravascular thrombosis, vasoconstriction, inflammation and remodelling of pulmonary arteries. Ensuing pulmonary hypertension leads to potentially fatal chronic right ventricle failure. Both inborn and acquired risk factors were identified. Pathogenesis of haemostatic disorders is not completely explained, and extrinsic coagulation pathway disorders may play a role in CTEPH aetiology.. To evaluate levels of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in CETPH, and to delineate their role in the disease pathogenesis.. Plasma concentrations of TF and TFPI were evaluated in 21 CTEPH patients, in 12 patients with pulmonary arterial hypertension (PAH), in 55 APE survivors without persistent pulmonary hypertension after at least 6 months from the acute episode, and in 53 healthy volunteers (control group C). Most patients were treated with vitamin K antagonists (VKA), and some with unfractionated or low molecular weight heparin. Exclusion criteria included malignancy, inflammation, and recent operation.. Tissue factor concentration was lower in CTEPH and in post-APE patients, not stratified by anticoagulation modality, as compared to control group (p = 0.042; p = 0.011) and PAH group (p = 0.024, p = 0.014). Patients with CTEPH and post-APE on adequate VKA-anticoagulation had similar TF concentration to group C. TFPI concentration was similar in CETPH and post-APE patients irrespective of anticoagulation, and higher as compared to group C (respectively, p = 0.012; p = 0.024; p = 0.004). TFPI concentration was similar in patients with CETPH and in post-APE group, both on adequate VKA-anticoagulation when compared to group C. In the post-APE group, there was no significant difference in TFPI concentration between patients receiving adequate and subjects without anticoagulation. Group C was significantly (p = 0.000) younger than any other group, and showed correlation (r = 0.31) between age and TFPI concentration.. In CTEPH there is a high consumption of TF, leading to reduction in plasma concentration of TF and increase in TFPI. Adequate VKA-anticoagulation normalises TF and TFPI plasma concentrations, as is the case of APE survivors.

Topics: Adult; Aged; Anticoagulants; Humans; Hypertension, Pulmonary; Lipoproteins; Middle Aged; Pulmonary Embolism; Thromboplastin; Vitamin K; Young Adult

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

Topics: Animals; Antifibrinolytic Agents; Arterial Pressure; Autophagy; Beclin-1; Hypertension, Pulmonary; Male; Microtubule-Associated Proteins; Pulmonary Artery; Pulmonary Circulation; Pulmonary Embolism; Rats; Rats, Sprague-Dawley; Thromboplastin; Tranexamic Acid; Vascular Remodeling

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.

Topics: Animals; Disease Models, Animal; Gene Expression Regulation; Hypertension, Pulmonary; Male; Nerve Tissue Proteins; Pulmonary Embolism; Rats; Rats, Sprague-Dawley; Thromboplastin; Vascular Resistance

To develop and evaluate a multicolour flow cytometry method for analysis of microparticles (MPs) in fresh whole blood without any centrifugation steps or freezing/thawing procedure.. Flow cytometry was performed using a FC500 MPL cytometer. The compensation in the protocol was performed based on the platelet population. Polystyrene microspheres 0.50-1.27 μm were used for size position, and the MP gate was set as particles 0.5-1.0 μm. Whole blood was incubated with annexin V and antibodies to tissue factor (TF), platelets (CD41 and CD62P), monocyte (CD14) and endothelial cells (CD144). For comparison, MPs from platelet free supernatant was used. The TF activity was evaluated by Calibrated Automated Thrombogram.. Annexin V was used to distinguish true events from background noise. For standardization, each analysis included 10,000 events in the gate of platelets. There were 622(462-1001) MP(annV+)/10,000 platelets and of these, 66 (49-82)/10,000 platelets expressed TF. After correction for the individual platelet counts, the amount of circulating MP(annV+) was 17.1 (12.1-24.9) × 10(9)/L in whole blood, and of these, 10% (6-12%) expressed TF. The majority of the MPs expressed CD41, and 5.6% (2.2-6.9%) of these co-expressed TF. The amount of CD41 + MP(annV+) tended to correlate to the TF activity in whole blood. There was no correlation between the MP(annV+) in whole blood and MPs derived from platelet free supernatant. Patients with pulmonary arterial hypertension and stable coronary artery disease had increased concentrations of CD41 + MP(annV+) in whole blood.. This multicolour flow cytometry assay in whole blood mimics the in vivo situation by avoiding several procedure steps interfering with the MP count. By standardized quantification of MPs a reference interval of MPs can be created.

Topics: Annexin A5; Antibodies, Monoclonal; Antigens, CD; Blood Platelets; Calibration; Cell-Derived Microparticles; Coronary Artery Disease; Endothelial Cells; Familial Primary Pulmonary Hypertension; Female; Flow Cytometry; Humans; Hypertension, Pulmonary; Male; Microspheres; Middle Aged; Monocytes; Particle Size; Polystyrenes; Reference Values; Thromboplastin

Inflammation, endothelial dysfunction, and thrombosis contribute to the pathogenesis and development of human pulmonary arterial hypertension (PAH). The aim of this study was to investigate the effects of ruscogenin, a natural anti-inflammatory and anti-thrombotic agent, on the development of monocrotaline (MCT)-induced PAH in rats. Our results revealed that ruscogenin had favorable effects on hemodynamics and pulmonary vascular remodeling, preventing the development of PAH 3 weeks after MCT. In addition, ruscogenin resulted in markedly reduced expression of inflammatory cytokine and leukocyte infiltration via the inhibition of nuclear factor (NF)-κB activity in rat lungs. Ruscogenin also attenuated MCT-induced endothelial cell apoptosis in the remodeled pulmonary arterioles and rescued destruction of endothelial cell membrane proteins such as eNOS, caveolin-1, and CD31. Our findings suggest that ruscogenin might have therapeutic benefits for PAH patients.

Topics: Animals; Anti-Inflammatory Agents; Antihypertensive Agents; Arterial Pressure; Caveolin 1; Endothelium, Vascular; Familial Primary Pulmonary Hypertension; Hypertension, Pulmonary; Interleukin-1beta; Male; Monocrotaline; NF-kappa B; Nitric Oxide Synthase Type III; Platelet Endothelial Cell Adhesion Molecule-1; Rats; Rats, Sprague-Dawley; Spirostans; Thromboplastin

Evidence suggests a role of both innate and adaptive immunity in the development of pulmonary arterial hypertension. The complement system is a key sentry of the innate immune system and bridges innate and adaptive immunity. To date there are no studies addressing a role for the complement system in pulmonary arterial hypertension.. Immunofluorescent staining revealed significant C3d deposition in lung sections from IPAH patients and C57Bl6/J wild-type mice exposed to three weeks of chronic hypoxia to induce pulmonary hypertension. Right ventricular systolic pressure and right ventricular hypertrophy were increased in hypoxic vs. normoxic wild-type mice, which were attenuated in C3-/- hypoxic mice. Likewise, pulmonary vascular remodeling was attenuated in the C3-/- mice compared to wild-type mice as determined by the number of muscularized peripheral arterioles and morphometric analysis of vessel wall thickness. The loss of C3 attenuated the increase in interleukin-6 and intracellular adhesion molecule-1 expression in response to chronic hypoxia, but not endothelin-1 levels. In wild-type mice, but not C3-/- mice, chronic hypoxia led to platelet activation as assessed by bleeding time, and flow cytometry of platelets to determine cell surface P-selectin expression. In addition, tissue factor expression and fibrin deposition were increased in the lungs of WT mice in response to chronic hypoxia. These pro-thrombotic effects of hypoxia were abrogated in C3-/- mice.. Herein, we provide compelling genetic evidence that the complement system plays a pathophysiologic role in the development of PAH in mice, promoting pulmonary vascular remodeling and a pro-thrombotic phenotype. In addition we demonstrate C3d deposition in IPAH patients suggesting that complement activation plays a role in the development of PAH in humans.

Topics: Animals; Arterioles; Biomarkers; Cell Proliferation; Chronic Disease; Complement C3; Complement C3a; Complement C5a; Endothelium, Vascular; Fibrin; Gene Deletion; Humans; Hypertension, Pulmonary; Hypoxia; Mice; Mice, Inbred C57BL; Myocytes, Smooth Muscle; Platelet Activation; Pulmonary Artery; Thromboplastin; Up-Regulation

Pulmonary hypertension (PH) is a commonly recognized complication of chronic respiratory disease. Enhanced vasoconstriction, pulmonary vascular remodeling, and in situ thrombosis contribute to the increased pulmonary vascular resistance observed in PH associated with hypoxic lung disease. The tissue factor pathway regulates fibrin deposition in response to acute and chronic vascular injury. We hypothesized that inhibition of the tissue factor pathway would result in attenuation of pathophysiologic parameters typically associated with hypoxia-induced PH. We tested this hypothesis using a chronic hypoxia-induced murine model of PH using mice that overexpress tissue factor pathway inhibitor (TFPI) via the smooth muscle-specific promoter SM22 (TFPI(SM22)). TFPI(SM22) mice have increased pulmonary TFPI expression compared with wild-type (WT) mice. In WT mice, exposure to chronic hypoxia (28 d at 10% O(2)) resulted in increased systolic right ventricular and mean pulmonary arterial pressures, changes that were significantly reduced in TFPI(SM22) mice. Chronic hypoxia also resulted in significant pulmonary vascular muscularization in WT mice, which was significantly reduced in TFPI(SM22) mice. Given the pleiotropic effects of TFPI, autocrine and paracrine mechanisms for these hemodynamic effects were considered. TFPI(SM22) mice had less pulmonary fibrin deposition than WT mice at 3 days after exposure to hypoxia, which is consistent with the antithrombotic effects of TFPI. Additionally, TFPI(SM22) mice had a significant reduction in the number of proliferating (proliferating cell nuclear antigen positive) pulmonary vascular smooth muscle cells compared with WT mice, which is consistent with in vitro findings. These findings demonstrate that overexpression of TFPI results in improved hemodynamic performance and reduced pulmonary vascular remodeling in a murine model of hypoxia-induced PH. This improvement is in part due to the autocrine and paracrine effects of TFPI overexpression.

Topics: Animals; Cell Proliferation; Gene Expression Regulation; Hemodynamics; Hypertension, Pulmonary; Hypoxia; Lipoproteins; Lung; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Muscle, Smooth, Vascular; Proliferating Cell Nuclear Antigen; Thromboplastin

Procoagulant microparticles constitute valuable hallmarks of cell damage. Microparticles also behave as cellular effectors.. We hypothesized that the extent of the vascular cell damage measured by circulating microparticles could be related to the severity of pulmonary arterial hypertension (PAH).. Circulating biomarkers of vascular damage and cell activation were measured in blood samples from 20 patients with PAH. Samples were withdrawn from occluded pulmonary artery and jugular vein. Peripheral venous blood samples were obtained in 23 control subjects. The microparticle procoagulant abilities were quantified by functional prothrombinase and tissue factor assays and their cellular origin was determined.. Soluble vascular cellular adhesion molecule-1 and proinflammatory markers, such as monocyte chemoattractant protein-1 and highly specific C-reactive protein, were elevated in patients with PAH compared with control subjects. Microparticles bearing active tissue factor and CD105 (endoglin) were also elevated in patients with PAH compared with control subjects (29 +/- 13 vs. 16 +/- 6 fmol/L, P < 0.001, and 1.10 +/- 0.46 vs. 0.49 +/- 0.33 nmol/L phosphatidylserine equivalent, P < 0.001, respectively). A further increase in endothelium-derived CD105 microparticles was observed in pulmonary arterial blood compared with venous blood in patients with PAH (1.73 +/- 0.77, P = 0.038). Microparticles bearing active tissue factor were at a higher level in patients in functional class III and IV and who were walking fewer than 380 m with the six-minute-walk test.. Circulating markers of endothelium damage, proinflammatory markers, and cell stimulation estimated with circulating microparticles appear to be valuable tools in determining the severity of PAH.

Topics: Adult; Aged; Antigens, CD; Blood Coagulation; Blood Gas Analysis; C-Reactive Protein; Chemokine CCL2; Chemokine CCL5; Endoglin; Endothelium, Vascular; Female; Humans; Hypertension, Pulmonary; Inflammation; Lung; Male; Microcirculation; Middle Aged; Particle Size; Receptors, Cell Surface; Severity of Illness Index; Thromboplastin; Vascular Cell Adhesion Molecule-1

Pulmonary tumor thrombotic microangiopathy is an unusual malignancy-related respiratory complication characterized by multiple microthrombi and intimal myofibroblast proliferation. Its clinical manifestation is subacute respiratory failure with pulmonary hypertension. Herein is reported a case of pulmonary tumor thrombotic microangiopathy associated with gastric signet ring cell carcinoma. A 51-year-old woman with gastric cancer died of subacute respiratory failure. Autopsy showed gastric signet ring cell carcinoma with diffuse metastasis of pulmonary lymphatics and pleurae; every organ examined lacked a space-occupying tumor mass. Histologically, proliferated intimal myofibroblasts obliterated most of the pulmonary vascular lumen, and a few stenosed vascular lumina contained cancer cells. In addition, pulmonary vasculature associated with intimal proliferation contained microthrombi. Most cancer cells in the stomach and pulmonary lymphatics were typical signet ring cells, whereas those in vascular lesions were cells of poorly differentiated adenocarcinoma without mucous production. Consistent with a previous report, the latter expressed vascular endothelial growth factor (VEGF) and tissue factor (TF). The proliferated intimal myofibroblasts also expressed type 2A serotonin receptor (5-HT(2A)). These findings suggest that local expression of VEGF, TF, and 5-HT(2A) may be linked to the pathogenesis of this unusual pulmonary complication.

Topics: Carcinoma, Signet Ring Cell; Endothelium, Vascular; Fatal Outcome; Female; Humans; Hypertension, Pulmonary; Lung; Lung Neoplasms; Microcirculation; Middle Aged; Neoplastic Cells, Circulating; Receptor, Serotonin, 5-HT2A; Respiratory Insufficiency; Stomach Neoplasms; Thromboembolism; Thromboplastin; Vascular Endothelial Growth Factor A

Severe pulmonary arterial hypertension (PAH) occurs in idiopathic form and in association with diverse diseases. The pathological hallmarks are distal smooth muscle hypertrophy, obliteration of small pulmonary arteriole lumens, and disorganized cellular proliferation in plexiform lesions. In situ thrombosis is also observed. A detailed understanding of the disease progression has been hampered by the absence of an animal model bearing all the pathological features of human disease. To create a model with these characteristics, we gave young (200-g) rats monocrotaline 1 wk following left pneumonectomy; controls with vehicle treatment or sham operation were also studied. In experimental rats, pulmonary arteries had distal smooth muscle hypertrophy and proliferative perivascular lesions. The lesions had a plexiform appearance, occurred early in disease development, and were composed of cells expressing endothelial antigens. Three-dimensional microangiography revealed severe vascular pruning and disorganized vascular networks. We found that expression of tissue factor (TF), the membrane glycoprotein that initiates coagulation, facilitates angiogenesis, and mediates arterial injury in the systemic circulation, was increased in the pulmonary arterioles and plexiform-like lesions of the rats. TF was also heavily expressed in the vessels and plexiform lesions of humans with pulmonary arterial hypertension. We conclude that plexiform-like lesions can be reproduced in rats, and this model will facilitate experiments to address controversies about the role of these lesions in PAH. Increased TF expression may contribute to the prothrombotic diathesis and vascular cell proliferation typical of human disease.

Topics: Angiography; Animals; Cell Proliferation; Disease Models, Animal; Endothelial Cells; Humans; Hypertension, Pulmonary; Hypertrophy, Right Ventricular; Male; Monocrotaline; Pneumonectomy; Pulmonary Artery; Rats; Rats, Sprague-Dawley; Thromboplastin; Vascular Endothelial Growth Factor Receptor-2; von Willebrand Factor

Topics: Animals; Disease Models, Animal; Humans; Hypertension, Pulmonary; Monocrotaline; Pneumonectomy; Pulmonary Artery; Radiography; Rats; Thromboplastin; Vascular Endothelial Growth Factor Receptor-2

The stress-responsive serum- and glucocorticoid-inducible kinase Sgk-1 is involved in osmoregulation and cell survival and may contribute to fibrosis and hypertension. However, the function of Sgk-1 in vascular remodeling and thrombosis, 2 major determinants of pulmonary hypertension (PH), has not been elucidated. We investigated the role of Sgk-1 in thrombin signaling and tissue factor (TF) expression and activity in pulmonary artery smooth muscle cells (PASMC). Thrombin increased Sgk-1 activity and mRNA and protein expression. H2O2 similarly induced Sgk-1 expression. Antioxidants, dominant-negative Rac, and depletion of the NADPH oxidase subunit p22phox diminished thrombin-induced Sgk-1 expression. Inhibition of p38 mitogen-activated protein kinase, phosphatidylinositol 3-kinase, and phosphoinositide-dependent kinase-1 prevented thrombin-induced Sgk-1 expression. Thrombin or Sgk-1 overexpression enhanced TF expression and procoagulant activity, whereas TF upregulation by thrombin was diminished by kinase-deficient Sgk-1 and was not detectable in fibroblasts from mice deficient in sgk-1 (sgk1(-/-)). Similarly, dexamethasone treatment failed to induce TF expression and activity in lung tissue from sgk1(-/-) mice. Transcriptional induction of TF by Sgk-1 was mediated through nuclear factor kappaB. Finally, Sgk-1 and TF proteins were detected in the media of remodeled pulmonary vessels associated with PH. These data show that thrombin potently induces Sgk-1 involving NADPH oxidases, phosphatidylinositol 3-kinase, p38 mitogen-activated protein kinase, and phosphoinositide-dependent kinase-1, and that activation of nuclear factor kappaB by Sgk-1 mediates TF expression and activity by thrombin. Because enhanced procoagulant activity can promote pulmonary vascular remodeling, and Sgk-1 and TF were present in the media of remodeled pulmonary vessels, this pathway may play a critical role in vascular remodeling in PH.

Topics: 3-Phosphoinositide-Dependent Protein Kinases; Animals; Cells, Cultured; Humans; Hypertension, Pulmonary; Immediate-Early Proteins; Mice; Mice, Knockout; Muscle, Smooth, Vascular; NADPH Oxidases; NF-kappa B; Oxidation-Reduction; p38 Mitogen-Activated Protein Kinases; Phosphatidylinositol 3-Kinases; Protein Serine-Threonine Kinases; Pulmonary Artery; Reactive Oxygen Species; Thrombin; Thromboplastin

The p21-activated serine/threonine kinases (PAK) play an important role in a variety of cellular functions. However, their role in the smooth muscle response to thrombin, which is activated upon vascular injury and promotes vascular remodelling processes, is not resolved. Here we investigated the role of PAK in thrombin signalling and regulation of tissue factor (TF), the activator of the extrinsic coagulation cascade, in pulmonary artery smooth muscle cells (PASMC), the main cell type responsible for vascular remodelling in pulmonary hypertension. PAK was rapidly phosphorylated in response to thrombin. Thrombin and active PAKT423E phosphorylated p38 MAP kinase (p38MAPK), ERK1/2, phosphatidylinositol-dependent kinase-1 (PDK1) and protein kinase B/Akt (PKB) whereas kinase-deficient PAK1 prevented activation of these kinases by thrombin. In addition, kinase- deficient MKK3 inhibited activation of PDK1 and PKB by thrombin. Further, thrombin and active PAK1 induced TF expression and promoter activity while kinase-deficient PAK1 diminished thrombin-induced TF upregulation. Moreover, kinase-deficient MKK3, PDK1 and PKB inhibited thrombin- and PAK-dependent TF expression and promoter activity. Together these findings show that PAK is a critical element of thrombin signalling in PASMC which is involved in the regulation of TF expression by sequentially activating MKK3/p38MAPK, PDK1 and PKB. Thus, PAK may play an important role in promoting vascular remodelling processes in pulmonary hypertension.

Topics: 3-Phosphoinositide-Dependent Protein Kinases; Cells, Cultured; Enzyme Activation; Humans; Hypertension, Pulmonary; MAP Kinase Kinase 3; MAP Kinase Signaling System; Muscle, Smooth, Vascular; Mutation; p21-Activated Kinases; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-akt; Pulmonary Artery; Recombinant Proteins; Thrombin; Thromboplastin; Transfection

Topics: Animals; Disease Models, Animal; Humans; Hypertension, Pulmonary; Rats; Rats, Sprague-Dawley; Thromboplastin; Tunica Intima

Although dysfunctional endothelium, vasoconstriction, and in situ thrombosis are characteristics of primary pulmonary hypertension, the role that plasma vasomotor and coagulation factors play in this phenomenon are not completely understood. The aim of this work was to ascertain the diagnostic value of endothelin-1, thrombomodulin, tissue factor, and tissue factor pathway inhibitor, as well as their correlation with endothelial dysfunction in primary pulmonary hypertension patients. We analyzed the plasmatic concentration and chromogenic of the above-mentioned molecules using immunoenzymatic techniques. Patients were divided into responders and nonresponders on the basis of their hemodynamic response to a vasodilator trial. We found a continuous increase in endothelin-1 levels and a continuous decrease in functional tissue factor in the control group, responders, and nonresponders, respectively. Moreover, the patients showed a moderate decrease in thrombomodulin levels compared with the control group, without statistical significance. These results support a previous description of a decrease in thrombomodulin levels in primary pulmonary hypertension patients and suggests that an alteration of endothelin-1 and functional tissue factor could be related to a worsening of endothelial function and, indirectly, with the clinical severity of primary pulmonary hypertension.

Topics: Endothelin-1; Endothelium, Vascular; Humans; Hypertension, Pulmonary; Lipoproteins; Prognosis; Thrombomodulin; Thromboplastin; von Willebrand Factor

Human plasma contains an inhibitor of tissue factor-initiated coagulation known as the lipoprotein-associated coagulation inhibitor (LACI) or also known as the extrinsic pathway inhibitor (EPI). A competitive fluorescent immunoassay was developed to measure the plasma concentration of LACI in samples from normal individuals and patients with a variety of diseases. The LACI concentration in an adult control population varied from 60% to 160% of the mean with a mean value corresponding to 89 ng/mL or 2.25 nmol/L. Plasma LACI levels were not decreased in patients with severe chronic hepatic failure, warfarin therapy, primary pulmonary hypertension, thrombosis, or the lupus anticoagulant. Plasma LACI antigen was decreased in some, but not all patients with gram-negative bacteremia and evidence for disseminated intravascular coagulation. Plasma LACI levels were elevated in women undergoing the early stages of labor (29%), in patients receiving intravenous tissue-type plasminogen activator (45%), and in patients receiving intravenous heparin (375%). A radioligand blot of the pre- and post-heparin plasma samples shows the increase to be in a 40-Kd form of LACI. Very low levels of plasma LACI antigen were found in patients with homozygous abetalipoproteinemia and hypobetalipoproteinemia, diseases associated with low plasma levels of apolipoprotein B containing lipoproteins. Following the injection of heparin into one patient with homozygous abetalipoproteinemia, the plasma LACI antigen level increased to a level comparable with that in normal individuals after heparin treatment.

Topics: Abetalipoproteinemia; Antibodies, Monoclonal; Apolipoproteins E; Cell Line; Factor VII; Female; Fluorescent Antibody Technique; Humans; Hypertension, Pulmonary; Labor, Obstetric; Lipoproteins; Pregnancy; Protease Inhibitors; Reference Values; Sepsis; Tangier Disease; Thromboplastin; Thrombosis

Topics: Arteriosclerosis; Arteritis; Cholesterol; Humans; Hypercholesterolemia; Hypertension; Hypertension, Pulmonary; Lung; Pulmonary Artery; Thromboplastin; Thrombosis

Topics: Amniotic Fluid; Animals; Dogs; Factor XI Deficiency; Hypertension; Hypertension, Pulmonary; Thromboplastin