thromboplastin and Fibrosis

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

1. The aim of the present review is to discuss: (i) the role of tissue factor (TF) in the heart and focus on its potential role in maintaining normal extracellular cardiac homeostasis; (ii) the means by which TF may be contributing to extracellular matrix regulation and vascular maintenance; and (iii) potential mechanisms whereby reduced TF expression leads to cardiac fibrosis. 2. Tissue factor is the main initiator of the coagulation cascade in response to tissue injury, but it is also involved in numerous other biological processes, including angiogenesis, cell migration, apoptosis, metastasis and inflammation. 3. Tissue factor is implicated in cardiovascular disease and its localization and level of expression in cardiomyocytes suggests a unique role in maintaining the structure and function of cardiac muscle. 4. It has been shown that TF(-/-) mice die in utero as a result of disrupted yolk sac vasculature. Low-TF mice, which have transgenic expression of TF at less than 1% of normal levels, are rescued from lethality. 5. Low-TF mice develop cardiac fibrosis in a gender-dependent manner that may be dependent on differential expression of urokinase plasminogen activator. 6. Intracardiac bleeding in low-TF mice may occur as a result of a primary haemostasis defect and/or as a result of disrupted vascular maintenance. The mechanism, when elucidated, will have important therapeutic implications and may provide novel strategies for the treatment of cardiac fibrosis.

Topics: Animals; Fibrosis; Heart; Humans; Myocardium; Thromboplastin

Pleural fibrosis resembles fibrosis in other tissues and can be defined as an excessive deposition of matrix components that results in the destruction of normal pleural tissue architecture and compromised function. Pleural fibrosis may be the consequence of an organised haemorrhagic effusion, tuberculous effusion, empyema or asbestos-related pleurisy and can manifest itself as discrete localised lesions (pleural plaques) or diffuse pleural thickening and fibrosis. Although the pathogenesis is unknown, it is likely that the complex interactions between resident and inflammatory cells, profibrotic mediators and coagulation, and fibrinolytic pathways are integral to pleural remodelling and fibrosis. It is generally considered that the primary target cell for pleural fibrosis is the subpleural fibroblast. However, increasing evidence suggests that mesothelial cells may also play a significant role in the pathogenesis of this condition, both by initiating inflammatory responses and producing matrix components. A greater understanding of the interactions between pleural and inflammatory cells, cytokines and growth factors, and blood derived proteins is required before adequate therapies can be developed to prevent pleural fibrosis from occurring.

Topics: Asbestosis; Epithelium; Fibrinolysis; Fibrosis; Humans; Platelet-Derived Growth Factor; Pleura; Pleural Diseases; Pleurisy; Thromboplastin; Transforming Growth Factor beta

Myocardial ischemic injury after heart transplantation is associated with subsequent development of graft vasculopathy. Both vitronectin receptor (integrin alpha(v)beta3) and tissue factor play key roles in vascular endothelial cell injury. Matrix metalloproteinases (MMPs) are activated in ischemic injury models.. Thirteen patients developed myocardial ischemic injury within 2 weeks of cardiac transplantation (ischemia group). These were compared with 10 transplantation patients who had no evidence of ischemia (control group). Endomyocardial biopsies were evaluated within 2 weeks of transplantation for alpha(v)beta3, tissue factor, and extracellular MMP inducer (EMMPRIN). At 1 year, MMPs were evaluated, and interstitial myocardial fibrosis was quantified. All patients underwent intravascular ultrasound at 1 month and 1 year after transplantation. Compared with control, the ischemia group demonstrated evidence of significant increased expression of alpha(v)beta3 (3.2-fold, P<0.001), tissue factor (2.5-fold, P<0.001), and EMMPRIN (1.9-fold, P=0.01). At 1 year, the ischemia group had a significant increase in myocardial fibrosis (24+/-1.8% versus 14+/-1.1%, P<0.001) and zymographic activity of MMP-2 (1.4-fold, P<0.001), MMP-3 (1.2-fold, P<0.001), and MMP-9 (1.3-fold, P=0.01). Coronary vasculopathy progression was also more advanced in the ischemia group (change in coronary maximal intimal thickness over 1 year 0.54+/-0.1 versus 0.26+/-0.06 mm; P=0.031).. Myocardial ischemic injury after cardiac transplantation is associated with upregulation of alpha(v)beta3, tissue factor, and activation of the MMP induction system, which may contribute to the subsequent development of allograft remodeling and vasculopathy.

Topics: Adult; Disease Progression; Enzyme Activation; Enzyme-Linked Immunosorbent Assay; Female; Fibrosis; Heart Transplantation; Humans; Immunoblotting; Immunohistochemistry; Male; Matrix Metalloproteinases; Middle Aged; Models, Cardiovascular; Myocardial Ischemia; Receptors, Vitronectin; Thromboplastin; Ultrasonography; Up-Regulation

High-performance athletes can develop symptomatic arterial flow restriction during exercise caused by endofibrosis. The pathogenesis is poorly understood; however, coagulation enzymes, such as tissue factor (TF) and coagulation factor Xa, might contribute to the fibrotic process, which is mainly regulated through activation of protease-activated receptors (PARs). Therefore, the aim of this explorative study was to evaluate the presence of coagulation factors and PARs in endofibrotic tissue, which might be indicative of their potential role in the natural development of endofibrosis.. External iliac arterial specimens with endofibrosis (n = 19) were collected during surgical interventions. As control, arterial segments of the external iliac artery (n = 20) were collected post mortem from individuals with no medical history of cardiovascular disease who donated their body to medical science. Arteries were paraffinized and cut in tissue sections for immunohistochemical analysis. Positive staining within lesions was determined with ImageJ software (National Institutes of Health, Bethesda, Md).. Endofibrotic segments contained a neointima, causing intraluminal stenosis, which was highly positive for collagen (+150%; P < .01) and elastin (+148%; P < .01) in comparison with controls. Intriguingly, endofibrosis was not limited to the intima because collagen (+213%) and elastin (+215%) were also significantly elevated in the media layer of endofibrotic segments. These findings were accompanied by significantly increased α-smooth muscle actin-positive cells, morphologically compatible with the presence of myofibroblasts. In addition, PAR1 and PAR4 and the membrane receptor TF were increased as well as coagulation factor X.. We showed that myofibroblasts and the accompanying collagen and elastin synthesis might be key factors in the development of endofibrosis. The special association with increased presence of PARs, factor X, and TF suggests that protease-mediated cell signaling could be a contributing component in the mechanisms leading to endofibrosis.

Topics: Adult; Aged; Aged, 80 and over; Athletes; Athletic Performance; Cadaver; Case-Control Studies; Collagen; Constriction, Pathologic; Elastin; Factor X; Female; Fibrosis; Humans; Iliac Artery; Male; Middle Aged; Myofibroblasts; Peripheral Arterial Disease; Receptor, PAR-1; Receptors, Thrombin; Thromboplastin; Up-Regulation; Vascular Remodeling; Young Adult

The release of neutrophil extracellular traps (NETs) represents a novel neutrophil effector function in systemic lupus erythematosus (SLE) pathogenesis. However, the molecular mechanism underlying NET release and how NETs mediate end-organ injury in SLE remain elusive.. NET formation and NET-related proteins were assessed in the peripheral blood and biopsies from discoid lupus and proliferative nephritis, using immunofluorescence, immunoblotting, quantitative PCR and ELISA. Autophagy was assessed by immunofluorescence and immunoblotting. The functional effects of NETs in vitro were assessed in a primary fibroblast culture.. Neutrophils from patients with active SLE exhibited increased basal autophagy levels leading to enhanced NET release, which was inhibited in vitro by hydroxychloroquine. NETosis in SLE neutrophils correlated with increased expression of the stress-response protein REDD1. Endothelin-1 (ET-1) and hypoxia-inducible factor-1α (HIF-1α) were key mediators of REDD1-driven NETs as demonstrated by their inhibition with bosentan and L-ascorbic acid, respectively. SLE NETs were decorated with tissue factor (TF) and interleukin-17A (IL-17A), which promoted thrombin generation and the fibrotic potential of cultured skin fibroblasts. Notably, TF-bearing and IL-17A-bearing NETs were abundant in discoid skin lesions and in the glomerular and tubulointerstitial compartment of proliferative nephritis biopsy specimens.. Our data suggest the involvement of REDD1/autophagy/NET axis in end-organ injury and fibrosis in SLE, a likely candidate for repositioning of existing drugs for SLE therapy. Autophagy-mediated release of TF-bearing and IL-17A-bearing NETs provides a link between thromboinflammation and fibrosis in SLE and may account for the salutary effects of hydroxychloroquine.

Topics: Autophagy; Cell Culture Techniques; Extracellular Traps; Fibroblasts; Fibrosis; Humans; Inflammation; Interleukin-17; Lupus Erythematosus, Systemic; Signal Transduction; Thromboplastin; Thrombosis; Transcription Factors

Hypercoagulability is associated with chronic kidney disease (CKD). Tissue factor/factor VIIa complex and factor Xa in the coagulation cascade are known to activate protease-activated receptor 2 (PAR2), and to cause inflammation and tissue injury. Although PAR2 is highly expressed in the kidney, it is unclear whether PAR2 plays a pathogenic role in CKD. To test this, we fed the mice lacking Par2 (F2rl1

Topics: Adenine; Animals; Enzyme-Linked Immunosorbent Assay; Factor V; Factor Xa; Fibrin; Fibrosis; Gene Expression Regulation; Inflammation; Kidney; Kidney Diseases; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Oxidative Stress; Receptor, PAR-2; Renal Insufficiency, Chronic; Thromboplastin

Neonatal respiratory distress syndrome can progress to bronchopulmonary dysplasia (BPD), a serious pulmonary fibrotic disorder. Given the involvement of the extrinsic coagulation cascade in animal models of lung fibrosis, we examined its role in BPD. We observed a higher number of neutrophils expressing tissue factor (TF) in bronchoalveolar lavage fluid (BALF) from infants with BPD than from those with uncomplicated respiratory distress syndrome together with a parallel decrease in TF and connective tissue growth factor (CTGF) in BALF supernatants during the disease course. The involvement of coagulation in the fibrotic process associated with BPD was further evaluated by treating primary human colonic myofibroblasts with BALF supernatants from infants with BPD. These human colonic myofibroblasts demonstrated an enhanced C5a- and thrombin-dependent migration. Moreover, they expressed TF in an endothelin-1-dependent manner, with subsequent activation of the extrinsic coagulation cascade and CTGF production mediated by protease-activator receptor-1 signaling. These data provide a novel mechanism for the development of BPD and indicate that endothelin-1 signaling contributes to fibrosis by upregulating a TF/thrombin amplification loop responsible for CTGF production, and offer novel and specific therapeutic targets for pulmonary fibrotic disease.

Topics: Blotting, Western; Bronchoalveolar Lavage Fluid; Bronchopulmonary Dysplasia; Cells, Cultured; Colon; Complement C5a; Connective Tissue Growth Factor; Endothelin-1; Female; Fibrosis; Green Fluorescent Proteins; Humans; Immunohistochemistry; Infant, Newborn; Lung; Male; Microscopy, Fluorescence; Myofibroblasts; Receptor, Anaphylatoxin C5a; Receptor, PAR-1; Receptors, Complement; Respiratory Distress Syndrome, Newborn; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Thrombin; Thromboplastin

The extrinsic coagulation cascade is involved in the fibrotic process, via thrombin-dependent induction of CCN2 (connective tissue growth factor) expression. Given the previously reported activation of the coagulation system in systemic sclerosis (SSc), we undertook the present study to investigate the involvement of cross-talk between the tissue factor (TF)-thrombin axis and endothelin 1 (ET-1) signaling in the fibrotic activity of SSc.. Human colonic myofibroblasts (HCMFs) from 6 patients with SSc and gastrointestinal symptoms and from 6 control subjects were isolated and cultured under various conditions. Messenger RNA and protein levels of TF, CCN2, and endothelin receptor A (ET(A) ) were investigated. Collagen production and migratory activity of HCMFs were further assessed.. HCMFs from SSc patients demonstrated increased basal CCN2 production, collagen deposition, and migration rate, in a thrombin-dependent manner. Increased TF expression was also observed in SSc HCMFs. Subsequent activation of the extrinsic coagulation system resulted in thrombin-dependent enhancement of ET(A) expression. ET(A) overexpression led to further increases in both TF expression and fibrotic activity in HCMFs. Moreover, inhibition of ET-1 signaling by bosentan abolished the TF-mediated fibrotic capacity of HCMFs.. Tissue factor-thrombin signaling is involved in the increased fibrotic activity of HCMFs from patients with SSc. Moreover, the up-regulation of ET(A) expression by thrombin and the effect of ET-1 in the induction of TF expression indicate an amplification loop for enhanced collagen deposition. Therapeutic interventions targeting the extrinsic coagulation system or ET-1 signaling may provide clinical benefit by breaking this vicious circle.

Topics: Cell Movement; Cell Proliferation; Collagen Type I; Colon; Connective Tissue Growth Factor; Fibrosis; Humans; Myofibroblasts; Receptor, Endothelin A; Receptor, PAR-1; Scleroderma, Systemic; Signal Transduction; Thrombin; Thromboplastin; Up-Regulation

Tissue factor (TF) initiates coagulation, regulates hemostasis, and plays a critical role in mediating arterial thrombosis. TF is up-regulated in vascular smooth muscle cells (VSMCs) in atherosclerosis and arterial injury. To examine the biologic role of VSMC-derived TF, we crossed TF(flox/flox) mice with SM22alphaCre(+/-) mice. TF mRNA and activity were decreased in the aortic media of TF-deficient mice by 96% and 94.8%, respectively. There were no differences in TF activity measured in plasma or concentrated microparticles. TF-deficient mice were generated with the expected frequency, showed no evidence of bleeding or increased mortality, and had similar activated partial thromboplastin and tail vein bleeding times. Thrombus-mediated flow reduction in response to ferric chloride injury of the carotid arteries was significantly attenuated in VSMC-specific TF-deficient. Stable occlusion was seen in 11 of 12 wild-type mice, but in only 6 of 16 VSMC-specific TF-deficient mice (P = .001). These data suggest that VSMC-derived TF is critical in a macrovascular model of arterial thrombosis. This mouse model should be valuable in determining the contribution of VSMC-derived TF in other TF-mediated phenomena, such as restenosis.

Topics: Animals; Aorta; Carotid Artery Thrombosis; Chlorides; Enzyme-Linked Immunosorbent Assay; Female; Ferric Compounds; Fibrosis; Immunohistochemistry; Male; Mice; Mice, Mutant Strains; Muscle, Smooth, Vascular; Myocardium; Myocytes, Smooth Muscle; Noxae; Reverse Transcriptase Polymerase Chain Reaction; Thromboplastin; Thrombosis

Obesity and insulin resistance are associated with accelerated macrovascular and microvascular coronary disease, cardiomyopathic phenomena, and increased concentrations and activity in blood of plasminogen activator inhibitor type 1 (PAI-1), the primary physiological inhibitor of fibrinolysis.. To determine whether hypofibrinolysis in blood and tissues and its potential sequelae could be attenuated pharmacologically, we studied genetically modified obese mice. By 10 weeks of age, obese mice exhibited increases in left ventricular weight and glucose and immunoreactive insulin in blood. PAI-1 activity in blood measured spectrophotometrically was significantly elevated as well. The difference compared with values in lean controls widened by 20 weeks of age. Perivascular fibrosis in coronary arterioles and small coronary arteries was evident in obese mice 10 and 20 weeks of age, paralleling increases in PAI-1 and tissue factor expression evident by immunohistochemical image analysis, in situ hybridization, and reverse transcription-polymerase chain reaction. Inhibition of ACE activity initiated in obese mice 10 weeks of age and continued for 20 weeks arrested the increase in PAI-1 activity in blood and in cardiac PAI-1 and tissue factor mRNA as well as coronary perivascular fibrosis.. Thus, inhibition of proteo(fibrino)lysis and augmented tissue factor expression in the heart precede and may contribute to the coronary perivascular fibrosis seen with obesity and insulin resistance. Furthermore, inhibition of ACE activity can attenuate all 3 phenomena.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Glucose; Body Weight; Coronary Vessels; Diabetes Mellitus; Fibrinolysis; Fibrosis; Heart Ventricles; Immunohistochemistry; In Situ Hybridization; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Myocardium; Obesity; Organ Size; Peptidyl-Dipeptidase A; Plasminogen Activator Inhibitor 1; RNA, Messenger; Thiazepines; Thromboplastin