Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0034069 (pulmonary fibrosis)
 7,050 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To clarify the role of thrombin in fibroblast growth and the development of pulmonary fibrosis in bleomycin-induced interstitial lung disease, we examined the relationship of thrombin activity to fibroblast growth-stimulating activity (FGA) in bronchoalveolar lavage fluid (BALF) from bleomycin-treated rats. Male Wistar rats were given a single intratracheal injection of bleomycin, bronchoalveolar lavage was performed 2, 6 and 15 days later, and the BALF was assayed for thrombin activity and FGA. Higher FGA than the control value was detected in the BALF from rats on Day 6 after bleomycin administration. In bleomycin-treated rats, thrombin activity in the BALF was significantly elevated on Day 2, and maximal on Day 6. The FGA of the BALF from bleomycin-treated rats on Day 6 was significantly decreased by its treatment with various thrombin inhibitors, such as alpha 1-antitrypsin, antithrombin III, hirudin and MD-805. On ammonium sulfate fractionation most of the thrombin activity was recovered in the fraction of 35-50% saturation in which most of the FGA was detected. These results suggest that the FGA of the BALF from bleomycin-treated rats was at least partly due to thrombin, and that thrombin is responsible, at least in part, for fibroblast growth and pulmonary fibrosis in bleomycin-induced interstitial lung disease.
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PMID:Significance of thrombin in bleomycin-induced pulmonary fibrosis. 170 28

In order to clarify the role of thrombin on the development of pulmonary fibrosis in diffuse interstitial lung diseases, we examined the relationship between fibroblast growth-stimulating activity (FGA) and thrombin activity in bronchoalveolar lavage fluid (BALF) from rats with bleomycin-induced interstitial lung disorders. Male Wistar strain rats (body weight about 200 g) were given a single intratracheal injection of 0.9 mg bleomycin, and bronchoalveolar lavage was performed on days 2, 6 and 15. The BALF was centrifuged at 250 X g for 10 min to remove cells, and then the supernatant was recentrifugation at 27,000 X g for 40 min to remove pulmonary surfactants. The supernatant (10 ml) was dialyzed overnight against distilled water, frozen at -70 degrees C, freeze-dried, and resuspended in 2 ml of Dulbecco's modified Eagle medium (concentrated 5-fold). The 5-fold concentrated BALF was added to rat lung fibroblast culture media, and assayed for cytotoxic activity and FGA. Thrombin activity in 250 X g supernatant was measured by using fluorescence assay with the synthetic peptide substrate, Boc-Val-Pro-Arg-4-methylcoumaryl-7-amide. Histological examination showed a prominent increase in fibroblast number in the pulmonary interstitium on day 6, and transformation of fibroblasts into mature forms, fibrocytes, on day 15. On day 2 after bleomycin administration, no FGA was seen but cytotoxic activity was detected in the BALF. On day 6, the cytotoxic activity was not found, whereas FGA showed a significantly higher level than the control value. On day 15, the FGA decreased to the control value.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The role of thrombin on lung fibroblast growth and fibrosis in bleomycin-induced lung disorder]. 170 10

To clarify the role of thrombin in fibroblast growth and the development of pulmonary fibrosis in bleomycin-induced interstitial lung disease, we examined the relationship of thrombin activity to fibroblast growth-stimulating activity (FGA) in bronchoalveolar lavage (BAL) fluid from bleomycin-treated rats. Male Wistar rats were given a single intratracheal injection of bleomycin, BAL was performed 2, 6, and 15 days later, and the BAL fluid was assayed for thrombin activity and FGA. Higher FGA than the control value was detected in the BAL fluid from rats on day 6 after bleomycin administration. In bleomycin-treated rats, thrombin activity in the BAL fluid was significantly elevated on day 2 and maximal on day 6. The FGA of the BAL fluid from bleomycin-treated rats on day 6 was significantly decreased by its treatment with various thrombin inhibitors, such as alpha 1-protease inhibitor, antithrombin III, hirudin, and MD-805. In our assay, purified rat thrombin also showed FGA in vitro, and its FGA was inhibited by the same concentrations of these thrombin inhibitors as those inhibiting the activity in the BAL fluid. On ammonium sulfate fractionation, most of the thrombin activity was recovered in the fraction of 35 to 50% saturation in which most of the FGA was detected. These results suggest that the FGA of the BAL fluid from bleomycin-treated rats was at least partly due to thrombin is responsible, at least in part, for fibroblast growth and pulmonary fibrosis in bleomycin-induced interstitial lung disease.
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PMID:Thrombin enhances lung fibroblast proliferation in bleomycin-induced pulmonary fibrosis. 171 76

In addition to its procoagulant properties, the serine protease thrombin increases endothelial permeability, stimulates granulocyte adherence, and serves as a fibroblast mitogen. We demonstrate that thrombin is mitogenic for human lung fibroblasts in vitro. The mitogenic effect of thrombin is associated with an increase in the expression of the ligand PDGF-AA and up-regulation of PDGF alpha-receptor. Since scleroderma (systemic sclerosis; SSc) is characterized by widespread microvascular injury and is frequently complicated by pulmonary fibrosis, we sought to determine the level of thrombin activity in bronchoalveolar lavage (BAL) fluid from SSc patients and normal controls. We report a significantly higher level of thrombin activity in BAL fluid from SSc patients compared with normal controls (P < 0.001). Taken together, the high levels of thrombin in BAL fluid and its demonstrated mitogenicity for lung fibroblasts suggest an important role for thrombin in the pathogenesis of SSc and perhaps other fibrotic lung diseases.
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PMID:Scleroderma bronchoalveolar lavage fluid contains thrombin, a mediator of human lung fibroblast proliferation via induction of platelet-derived growth factor alpha-receptor. 751 Sep 86

Pulmonary fibrosis commonly develops in systemic sclerosis. We assessed the role of thrombin in promoting fibroblast proliferation in the lungs in this disorder. Bronchoalveolar lavage fluid (BALF) thrombin concentrations were higher in ten patients with systemic sclerosis than in 12 healthy controls (14.6 vs 3.6 nmol/L, p < 0.02), but values in patients with cryptogenic fibrosing alveolitis (n = 10) or sarcoidosis (n = 10) were not increased. BALF from all patients induced fibroblast proliferation. This proliferation was attenuated by thrombin inhibitors for BALF from systemic sclerosis patients only. We suggest thrombin contributes to lung fibroblast proliferation in this disorder.
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PMID:Role of thrombin in pulmonary fibrosis. 756 89

Thrombin is a multifunctional enzyme generated at sites of vascular injury, and is known to be increased in the lungs in some types of fibrotic lung disease. In this study, to determine whether thrombin is associated with fibroblast growth and pulmonary fibrosis in these disorders, we examined whether a growth factor for fibroblasts (platelet-derived growth factor, PDGF) was released by thrombin-stimulated alveolar macrophages (AM). The culture supernatants of rat AM stimulated with 1 or 10 U/ml of thrombin showed a significant increase in fibroblast growth-stimulating activity (FGA). Pretreatment of the AM supernatant with anti-PDGF-AA antibody significantly decreased the FGA, but pretreatment with anti-PDGF-BB antibody did not. The supernatants of AM stimulated with thrombin also increased the growth of fibroblasts from the lungs of rats with bleomycin-induced lung injury. These results indicate that thrombin stimulates AM to release PDGF-AA, which is responsible, at least in part, for fibroblast growth and the development of pulmonary fibrosis in some types of fibrotic lung disease.
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PMID:Thrombin stimulates platelet-derived growth factor release by alveolar macrophages in rats--significance in bleomycin-induced pulmonary fibrosis. 939 19

Excessive procoagulant activity in the alveolar space may play a relevant role in the pathogenesis of pulmonary fibrosis. Hypercoagulability results from the disruption of the balance between the procoagulant and anticoagulant factors. The aim of this study was to assess the levels of molecular markers of the anticoagulant protein C (PC) pathway in the bronchoalveolar lavage fluid (BALF) and plasma of 11 patients with idiopathic pulmonary fibrosis (IPF), 14 with sarcoidosis and 16 with collagen vascular disease (CVD)-associated interstitial lung disease (CVD-ILD). Six healthy nonsmoking volunteers served as control subjects. BALF concentrations of the marker of clotting activation, thrombin- antithrombin III complex (TAT), in patients with sarcoidosis and CVD-ILD were significantly greater than those in control subjects. PC levels in BALF were markedly higher in patients with IPF (610 +/- 150 ng/ml), sarcoidosis (680 +/- 170 ng/ml), and CVD-ILD (1,580 +/- 600 ng/ml) than in control subjects (230 +/- 140 ng/ml). BALF concentrations of activated PC-PC inhibitor (APC-PCI) complex were significantly decreased in IPF (0.46 +/- 0.16 ng/ml), sarcoidosis (0. 43 +/- 0.11 ng/ml), and CVD-ILD (0.50 +/- 0.15 ng/ml) patients as compared with control subjects (1.08 +/- 0.23 ng/ml). APC-PCI/PC ratios were significantly lower in patients with IPF (2.70 +/- 1.74 ng/microg), sarcoidosis (1.94 +/- 0.82 ng/microg), and CVD-ILD (1.89 +/- 0.68 ng/microg) than in control subjects (15.91 +/- 8.45 ng/microg). Plasma levels of APC- PCI and the APC-PCI/PC ratio were also significantly decreased in patients with CVD-ILD as compared with control subjects. Overall, these findings suggest that decreased PC activation with increased procoagulant activity occurs in patients with ILD.
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PMID:Protein C anticoagulant system in patients with interstitial lung disease. 962 Sep 17

Thrombin is a multifunctional serine protease which plays a central role in haemostasis by regulating platelet aggregation and blood coagulation. It is formed from its precursor prothrombin following tissue injury and converts fibrinogen to fibrin in the final step of the clotting cascade. It also promotes numerous cellular effects including chemotaxis, proliferation, extracellular matrix turnover and release of cytokines. These actions of thrombin on cells have been implicated in tissue repair processes and in the pathogenesis of inflammatory and fibroproliferative disorders such as pulmonary fibrosis and atherosclerosis. Thrombin mediates its cellular effects by proteolytically activating cell surface receptors. Presently, two such receptors have been described and their roles in regulation of these functions are currently being investigated. The discovery of multiple thrombin receptors creates the possibility of selective receptor blockade of specific thrombin mediated events. New drugs with these actions should add to our current repertoire of thrombin inhibitors used to treat thrombotic diseases.
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PMID:Thrombin. 969 19

Activation of the coagulation system in the alveolar space plays an important role in the pathogenesis of interstitial lung disease (ILD) and pulmonary fibrosis. The protein C (PC) pathway is the main modulator of coagulation activation. This study evaluated whether dysfunction of the PC pathway is associated with increased collagen synthesis in the intraalveolar space of patients with ILD. This study comprised 22 patients with ILD; of these, five had idiopathic pulmonary fibrosis (IPF), nine had sarcoidosis-associated ILD, and eight had collagen vascular disease-associated ILD (CVD-ILD). Thrombin-antithrombin complex (TAT) was measured as a marker of coagulation activation. As markers of the PC pathway activity, the concentration of activated PC-PC inhibitor (APC-PCI) complex and the APC-PCI/PC ratio were measured and, as a marker of collagen synthesis, the concentration of aminoterminal propeptide of type III procollagen (PIIINP) was measured in bronchoalveolar lavage fluid (BALF) of ILD patients. TAT was significantly increased in BALF from ILD patients as compared to control subjects. The concentrations of PIIINP were significantly elevated in patients with ILD as compared to healthy subjects. In contrast, the concentration of APC-PCI and the values of APC-PCI/PC ratio were significantly decreased in BALF from patients with ILD. BALF concentration of PIIINP was significantly and inversely correlated with the concentration of APC-PCI and with the APC-PCI/PC ratio. These findings suggest that dysfunction of the protein C pathway may have important physiopathologic implications in the development of pulmonary fibrosis in ILD.
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PMID:Decreased protein C activation is associated with abnormal collagen turnover in the intraalveolar space of patients with interstitial lung disease. 1103 May 25

Dramatic activation of the coagulation cascade has been extensively documented for pulmonary fibrosis associated with acute and chronic lung injury. In addition to its role in hemostasis, thrombin exerts profibrotic effects via activation of the major thrombin receptor, protease-activated receptor-1. In this study, we examined the effect of the direct thrombin inhibitor, UK-156406 on fibroblast responses in vitro and on bleomycin-induced pulmonary fibrosis in rats. UK-156406 significantly inhibited thrombin-induced fibroblast proliferation, procollagen production, and connective tissue growth factor (CTGF) mRNA levels when used at equimolar concentration to the protease. Thrombin levels in bronchoalveolar lavage fluid and expression of thrombin and protease-activated receptor-1 in lung tissue were increased after intratracheal instillation of bleomycin. The characteristic doubling in lung collagen in bleomycin-treated animals (38.4 +/- 2.0 mg versus 17.1 +/- 1.4 mg, P < 0.01) was preceded by significant elevations in alpha1(I) procollagen and CTGF mRNA levels (3.0 +/- 0.4-fold and 6.3 +/- 0.4-fold respectively, (P < 0.01), and total inflammatory cell number. UK-156406, administered at an anticoagulant dose, attenuated lung collagen accumulation in response to bleomycin by 35 +/- 12% (P < 0.05), inhibited alpha1(I) procollagen and CTGF mRNA levels by 50% and 35%, respectively (P < 0.05), but had no effect on inflammatory cell recruitment. This is the first report showing that direct thrombin inhibition abrogates lung collagen accumulation in bleomycin-induced pulmonary fibrosis.
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PMID:Direct thrombin inhibition reduces lung collagen, accumulation, and connective tissue growth factor mRNA levels in bleomycin-induced pulmonary fibrosis. 1158 66


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