SEARCH · PubMed Health

Results for “PULMONARY FIBROSIS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

PubMed2006

[Differential therapy of pulmonary fibrosis].

Pulmonary fibrosis is the final outcome of a numerous and heterogeneous group of pulmonary disorders grouped together under the family of diffuse parenchymal lung diseases. Safe identification of the underlying condition is difficult but is the prerequisite for any therapeutic attempt. In principle, diffuse parenchymal lung diseases may be divided into those forms being triggered by an initial inflammatory process (e. g. sarcoidosis, hypersensitivity pneumonitis), and those being most likely triggered by epithelial injury (idiopathic pulmonary fibrosis). Steroids and immunosuppressants do have their role in treatment of the former group, although the efficacy on long-term outcome is not entirely clear. In contrast, steroids and immunosuppressants are only rarely helpful in the latter condition. Novel therapeutic strategies for the treatment of idiopathic pulmonary fibrosis are currently under preclinical or clinical assessment and include antioxidative agents and agents that block alveolar coagulation or different growth factors.

Antioxidants↗

PubMed2004

The role of apoptosis in pulmonary fibrosis.

Pulmonary fibrosis is a common response to various injuries to the lung. The resolution of a fibroproliferative response after lung injury is key to survival. Although there are various initiating factors or causes, the terminal stages are characterized by proliferation and progressive accumulation of connective tissue replacing normal functional parenchyma. Conventional therapy consisting of glucocorticoids or immunosuppressive drugs is usually ineffective in preventing progression of fibrosis. Further understanding of the molecular mechanisms of endothelial and epithelial cell injury, inflammatory reaction, fibroblast proliferation, collagen deposition and tissue remodeling, should lead to the development of effective treatments against pulmonary fibrosis. Evidence that apoptosis plays an important role in the pathophysiology of pulmonary fibrosis has been accumulated. We overview the role of apoptosis in each of the pathogenic events which have emerged from animal models and human tissue studies.

Animals↗

PubMed2007

An essential role for CCAAT/enhancer binding protein beta in bleomycin-induced pulmonary fibrosis.

Pulmonary fibrosis is characterized by inflammation, genesis of myofibroblasts, and abnormal tissue repair. Despite extensive research, its pathogenesis remains incompletely understood. Previously, the transcription factor CCAAT/enhancer binding protein beta (C/EBPbeta) was found to be a key regulator of myofibroblast differentiation in vitro, and to be involved in the acute phase and inflammatory responses. In an attempt to test the role of C/EBPbeta in the development of pulmonary fibrosis, experiments using C/EBPbeta null mice and their wild-type littermates were conducted. Our findings indicated that, compared to wild-type mice, animals deficient in C/EBPbeta showed significantly reduced fibrotic lesions and collagen deposition in the lung upon endotracheal injection of bleomycin. Further studies on the mechanisms by which C/EBPbeta regulates fibrosis indicated that knockout of C/EBPbeta attenuates inflammatory cytokine expression in bleomycin-treated mice. The reduced alpha-smooth muscle actin gene expression in either isolated lung fibroblasts or lung tissue from bleomycin or saline-treated C/EBPbeta deficient mice suggests that C/EBPbeta regulates myofibroblast differentiation during fibrosis. Consistent with this finding, cells from C/EBPbeta deficient mice exhibited higher proliferative rates than those from wild-type mice. These data suggest that C/EBPbeta plays an essential role in pulmonary fibrosis and that this role appears to be multifactorial with respect to cytokine expression, cell differentiation, and proliferation.

Actins↗

PubMed2002

Molecular mechanisms of pulmonary fibrosis.

Pulmonary fibrosis is the end-point of a numerous and heterogeneous group of disorders known as interstitial lung diseases (ILD). Lung fibrotic remodeling is characterized by fibroblast/myofibroblast activation, and excessive extracellular matrix accumulation leading to progressive organ dysfunction and usually terminal outcome. Treatment is largely ineffective primarily because few of the molecular mechanisms have been well defined to design appropriate targets for therapy. While the pathogenesis is incompletely understood, a growing body of evidence suggests two different pathogenic routes for developing pulmonary fibrosis. The inflammatory pathway, where a shift to the so-called T-helper 2 type cytokine networks is critical, and the epithelial pathway represented by idiopathic pulmonary fibrosis, by far the most aggressive ILD. In this pathway the inflammatory process is irrelevant, and the physiopathology seems to be dominated by epithelial cell injury and activation. Both routes may trigger a number of cytokines/growth factors inducing fibroblast migration/proliferation and phenotype change to myofibroblasts, with a consequent accumulation of extracellular matrix. An imbalance in matrix metalloproteinase/tissue inhibitors of metalloproteinases may contribute to alteration in extracellular matrix turnover and remodeling. This review will focus in some of the mechanisms involved in both prefibrotic pathways, as well as those involved in fibroblast activation and abnormal matrix deposition.

Animals↗

PubMed2006

Phospholipid concentration in lung lavage fluid as biomarker for pulmonary fibrosis.

Pulmonary surfactant comprised primarily of phospholipids is a phospholipid-protein complex synthesized by type II alveolar epithelial cells or Clara cells and secreted to the pulmonary alveoli. As changes have been found in phospholipid concentrations in the bronchoalveolar lavage fluid (BALF) of patients with pulmonary fibrosis, phospholipid is considered to be involved in the process of fibrois/fibrotic process. Therefore, we made a crystalline silica rat model and measured phospholipid concentrations in lung lavage fluid in order to study the relationship of phospholipid to particle-induced pulmonary fibrosis. Eight-week-old Wistar male rats (n = 35) were injected with 2 mg crystalline silica particles suspended in 0.4 ml physiological saline. Rats in the control group (n = 35) were injected with physiological saline only. There were 7 rats in each of the ten subgroups. Rats were sacrificed and dissected at 3 days, 1 wk, 1 mo, 3 mo, and 6 mo after injection. Bronchoalveolar lavage was conducted on bronchoalveoli recovered from the right lung of each rat, the lavage fluid was centrifuged, and the supernatant was used to measure phospholipid concentration. The results were compared with previously reported inflammation scores. Phospholipid concentrations in lung lavage fluid for the exposed group showed a statistically significant increase compared to the control group throughout the observation period. Moreover, when compared to histopathologically examined inflammation scores, a positive correlation was found between the two. Judging from the facts that phospholipid concentrations in lung lavage fluid increased and that this increase correlated with the severity of inflammation, this experiment indicated that phospholipids are involved in particle-induced lung disorders.

Animals↗

PubMed2002

Involvement of gelatinases (MMP-2 and MMP-9) in the development of airway inflammation and pulmonary fibrosis.

Pulmonary fibrosis has an aggressive course and is usually fatal an average of 3 to 6 years after the onset of symptoms. Pulmonary fibrosis is associated with deposition of extracellular matrix (ECM) components in the lung interstitium. Matrix metalloproteinases (MMPs) are a major group of proteinases known to regulate the ECM remodeling and so they are hypothesized to be important in the process of lung fibrosis. These led to the concept that modulation of airway remodeling including excessive proteolytic damage of the tissue may be of interest for future treatment. The excessive airway remodeling as a result of an imbalance in the equilibrium of the normal processes of synthesis and degradation of extracellular matrix components could argue in favor of antiprotease treatments. Moreover, these observations emphasize that effective therapies for these disorders must be given early in the natural history of the disease, prior to the development of expensive lung destruction and fibrosis.

Extracellular Matrix↗

PubMed1989

Early increases in pulmonary mRNA encoding procollagens and transforming growth factor-beta in mice sensitive to cyclophosphamide-induced pulmonary fibrosis.

Pulmonary fibrosis was induced 7 weeks after a single i.p. injection of cyclophosphamide (200 mg/kg b.wt.) in BALB/c mice; C57Bl/6 mice were unaffected. There was a corresponding strain variation in the effects of cyclophosphamide on levels of pulmonary mRNA encoding alpha 2I and alpha 1III procollagen, and transforming growth factor-beta. In BALB/c mice, the ratios of alpha 2I and alpha 1III procollagen mRNA to polyadenylated RNA were increased 1 week after cyclophosphamide injection. No increases in levels of either procollagen mRNA occurred in C57Bl/6 mice. The ratio of fibronectin mRNA to polyadenylated RNA was elevated to a similar extent in both murine strains during the 1st week after cyclophosphamide treatment. The pulmonary content of transforming growth factor-beta mRNA and its ratio to polyadenylated RNA increased 2-fold at 1 and 2 weeks in BALB/c but not C57Bl/6 mice. Thus, collagen accumulation in cyclophosphamide-sensitive mice is preceded by increased pulmonary alpha 2I and alpha 1III procollagen mRNA. The early strain selective elevation of transforming growth factor-beta mRNA in response to cyclophosphamide suggests a role, in vivo, for transforming growth factor-beta in drug-induced pulmonary fibrosis.

Animals↗

PubMed2002

Overview of pulmonary fibrosis.

Pulmonary fibrosis is a component of over 200 interstitial lung diseases. Some have known etiologies, however, for many diseases, the etiology remains unknown or obscure. This brief review examines the prevalence and classification of these diseases, the approach to be taken for the investigation of a patient suspected of having pulmonary fibrosis, the indications for the performance of lung biopsy, and current thoughts concerning the pathogenesis of the idiopathic forms of fibrotic lung disease. A brief review of established and emerging therapeutic strategies is included.

Humans↗

PubMed1996

Heparin attenuates bleomycin but not silica-induced pulmonary fibrosis in mice: possible relationship with involvement of myofibroblasts in bleomycin, and fibroblasts in silica-induced fibrosis.

Pulmonary fibrosis was elicited in mice or rats by the intratracheal instillation of bleomycin or silica. Daily injections of heparin significantly reduced the collagen deposition in bleomycin, but not in silica, injected mice, as evaluated by the lung hydroxyproline content on day 15 after instillation. Heparin also reduced the bleomycin-induced morbidity and mortality. Study of the broncho-alveolar lavage fluid (BAL) detected no significant change in the number of leucocytes or the amount of protein in heparin treated mice. Histologies of bleomycin instilled mice suggested that heparin did reduce the alveolar remodelling but not the alveolitis, evidenced by leucocytic infiltration. As detected by electron microscopy (EM), bleomycin increased the number of leucocytes and platelets within the alveolar capillaries but this was not significant ly reduced by heparin. The phenotype of the interstitial cell involved in these two types of pulmonary fibrosis was investigated by immunohistochemistry and EM. While in bleomycin injected animals the interstitial cells had the phenotype of an actin (alpha-actin in the rat) and lipid containing interstitial cell, with a poorly developed RE, in silica injected animals in contrast, the interstitial cells were without cytoplasmic actin or lipid but with a markedly developed endoplasmic reticulum (ER). Thus bleomycin and silica induced the growth of two different types of interstitial cells, the myofibroblast and the regular fibroblast, which might be a reason why heparin selectively inhibits bleomycin but not silica-induced fibrosis.

Animals↗

PubMed2004

Drug-induced pulmonary fibrosis.

Pulmonary fibrosis is characterized by the accumulation of excessive connective tissue in the lungs. Its causes include chronic administration of some drugs for example bleomycin, cyclophosphamide, amiodarone, procainamide, penicillamine, gold and nitrofurantoin; exposure to certain environmental factors such as gases, asbestos and silica and bacterial or fungal infections. Some systemic diseases also predispose to the disease for example rheumatoid arthritis and systemic lupus erythematosus. The disease is associated with release of oxygen radicals and some mediators such as tumor necrosis factor-alpha TNF-alpha, transforming growth factor-beta TGF-beta, PDGF, IGF-I, ET-I and interleukins 1, 4, 8 and 13. The symptoms of the disease include dyspnea, non-productive cough, fever and damage to the lung cells. It is diagnosed with the aid of chest radiography, high resolution computed tomographic scanning and the result of pulmonary function tests. Drug-induced pulmonary fibrosis may involve release of free oxygen radicals and various cytokines for example IL-Ibeta and TNF-alpha via activation of nuclear transcription factor NF-beta as in the case of bleomycin and mitomycin or via release of TGF-beta as in case of tamoxifen or via inhibition of macrophages' and lymphocytes' phospholipases as in the case of amiodarone with the resultant accumulation of phospholipids and reduction of the immune system.

Antioxidants↗

PubMedDate not supplied

Role of oxidative stress in pulmonary fibrosis.

Pulmonary fibrosis can be observed as an end state in a number of chronic inflammatory pulmonary diseases. Although the mechanisms by which lung fibrosis develops are not fully ascertained, recent findings suggest that oxidative stress may play an important role in the pathogenesis of tissue fibrosis affecting apoptosis of both structural and inflammatory cells and altering the cytokine microenvironment balance. Damage and alteration of alveolar epithelial cells is one of the hallmarks of interstitial lung fibrosis. Recently, it has been demonstrated that the presence of oxidative stress may lead to the damage, activation and/or apoptosis of alveolar epithelial cells either directly, through an imbalanced intracellular redox equilibrium, or indirectly, by activating redox-sensitive effector pathways, such as transcription factors and angiotensin converting enzyme, increasing the conversion of angiotensinogen into angiotensin II that can be considered a mediator of oxidative stress, capable of inducing apoptosis. Furthermore, it has been demonstrated that angiotensin II acts as a proinflammatory cytokine and is effective in activating fibroblasts through the release of transforming growth factor (TGF-beta). As well as activation, differentiation, proliferation and apoptosis of fibroblasts seem related to the oxidant/antioxidant balance, and the maintenance of a high intracellular level of reduced glutathione (GSH) is considered crucial in providing a reducing environment within the cell, able to protect against oxidative stress. In those conditions where oxidants, either inhaled or produced by inflammatory cell, increase, the ratio between GSH and oxidized glutathione (GSSH) may lower, influencing a variety of cellular redox-sensitive signaling processes such as the activation of nuclear factor-kB (NF-kB) and activator protein-1 (AP-1) that lead to a transcriptional up-regulation of a number of genes involved in inflammation and/or fibrogenesis, including cytokines [interleukin (IL)-1,, tumor necrosis factor (TNF-alpha), IL-6] chemokines (IL-8), adhesion molecules (VCAM-1, ICAM-1) and growth factors (GM-CSF). In addition, several studies have shown that oxidative stress may also affect the immune response by inducing an up-regulation of HLA-DR as well as the expression of two costimulatory molecules such as CD40 and CD86, determining a persistent state of immune activation, and affecting the Th1/Th2 balance, modulating the T-cell effector response towards the Th2 phenotype. It is clear that a better understanding of the precise sequence of events that make the difference between normal tissue repair and fibrosis, including the role played by oxidative stress, will certainly improve our therapeutic approach to pulmonary fibrosis.

Angiotensin II↗

PubMed2001

Differential mRNA expression of insulin-like growth factor-1 splice variants in patients with idiopathic pulmonary fibrosis and pulmonary sarcoidosis.

Insulin-like growth factor-1 (IGF-1) is a highly mitogenic polypeptide detectable in human lung. Using competitive reverse transcriptase/polymerase chain reaction (RT-PCR), expression of four IGF-1 transcripts was examined in bronchoalveolar lavage cells (BALC) from normal subjects, idiopathic pulmonary fibrosis (IPF), stage I/II (no fibrosis), and stage III/IV (confirmed fibrosis) pulmonary sarcoidosis patients, and fibroblast strains isolated from normal and IPF lungs. Transcripts studied were Class 1 and Class 2 (exons 1 or 2, respectively) with IGF-1Eb or IGF-1Ea (exons 5 or 6, respectively). Total IGF-1 expression was downregulated in BALC of both patients with IPF (p < 0.01) and patients with sarcoidosis (p < 0.04) compared with healthy subjects. In contrast, both constitutive (p < 0.003) and transforming growth factor-beta (TGF-beta)- induced (p < 0.02) IGF-1 expression was higher in fibrotic, compared with normal, fibroblasts. These changes were associated with differential expression of IGF-1 splice variants. Healthy subjects and sarcoidosis patients without fibrosis showed similar expression of Class 1/Class 2 and IGF-1Ea/IGF-1Eb. However, patients with fibrosis demonstrated discordant, increased relative abundance of Class 1 transcripts (p < 0.01). In parallel, all fibrosis patients failed to express Class 2, IGF-1Eb forms and sarcoidosis patients with fibrosis did not express the Class 1, IGF-1Eb variant either. Fibrotic fibroblasts expressed higher constitutive levels of Class 1, IGF-1Ea transcripts compared with normal fibroblasts. Class 2, IGF-1Eb forms were moderately expressed by fibroblasts only after stimulation with TGF-beta, which also further increased levels of Class 1, IGF-1Ea transcripts. Our findings suggest that transition from a healthy to a fibrotic phenotype occurs in association with a changing pattern of IGF-1 mRNA heterogeneity and leads us to hypothesize a potential role for specific IGF-1 variants in fibrogenesis.

Adult↗

PubMed1989

[Assessment of pulmonary hemodynamics in patients with idiopathic pulmonary fibrosis].

Pulmonary hemodynamics were assessed in 52 patients with idiopathic pulmonary fibrosis of which 25 were confirmed histopathologically. The study group consisted of 26 males and 26 females, of a mean age of 41 +/- 15 years. Pulmonary function studies revealed restrictive changes and increased elastic recoil. Mean vital capacity was 2.6 +/- 1.2 L, compliance - static 97 +/- 59 ml/cm H2O, dynamic 71 +/- 50 ml/cm H2O. Esophageal pressure was - 8.0 +/- 5.3 mm Hg. Mean pulmonary artery pressure was slightly elevated - 22.6 +/- 8.3 mm Hg. Transmural pulmonary pressure was 31.3 +/- 9.8 mm Hg, cardiac output was 7.6 +/- 3.8 L/min, pulmonary resistance 206 +/- 119 dyn sec cm-5. A mild hypoxemia was observed--PaO2 71.8 +/- 13.3 mm Hg. In part of the study group (27 subjects) the response to exercise was assessed. A mean increase of pulmonary artery pressure from 20.4 +/- 7.2 to 38.0 +/- 14.7 mm Hg and a decrease of PaO2 from 74.2 +/- 11.7 mm Hg to 62.5 +/- 15.3 mm Hg were found. Negative correlation was found between mean artery pulmonary pressure and arterial oxygen partial pressure, vital capacity and one-second forced expiratory volume, and a higher correlation between mean transmural pulmonary pressure and PaO2, VC, FEV1 and Cdyn.

Adolescent↗

PubMed1990

Pathobiology of pulmonary fibrosis.

Pulmonary fibrosis is characterized by an increase in lung matrix and alterations in the numbers and spatial relationships of lung parenchymal cells. The increase in matrix results from a proliferation and "activation" of fibroblasts (FB) with increased production and deposition of matrix macromolecules at sites of lung injury. Connective tissue cell activation is associated with increased gene expression of collagens, fibronectin, proteoglycans and other matrix components; cytoskeletal alterations; and probably also with changes in the expression of matrix receptors and matrix-degrading enzymes and inhibitors. The fibroproliferative reaction involves the participation of a variety of cytokines and inflammatory mediators by resident and inflammatory cells at sites of lung injury. Thickening of the alveolar wall can result secondary to matrix deposition within the interstitium and as a result of "mural incorporation" of organized airspace exudate. However, marked structural remodeling of the gas-exchange tissues, with the development of honeycomb lung, involves airspace fibrosis and alveolar collapse. The latter processes lead to areas of airspace obliteration secondary to airspace filling, and to fibrous adhesion of collapsed septa. The extent of airspace obliteration is determined largely by the severity or extent of epithelial injury. Although lung fibrosis is usually irreversible, the activated state is reversible after clearance of exudate and reepithelialization. A continuing and seemingly autonomous fibroproliferative reaction can result in the face of ongoing injury and delayed repair.

Animals↗

PubMed1995

Role of thrombin in pulmonary fibrosis.

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.

Alveolitis, Extrinsic Allergic↗

PubMed2006

Therapeutic effect of Chinese medicine formula DSQRL on experimental pulmonary fibrosis.

Pulmonary fibrosis (PF) is a restrictive lung disease that may occur idiopathically or as a complication of many diseases. The outcome of the current treatment by glucocorticoids remains very unsatisfactory. This study has tested a new Chinese medicine formula DSQRL for the treatment of experimental PF in comparison with prednisone. Seventy-two rats with PF induced by CCl(4) were randomly divided into four groups to undertake the treatment of either (a) high dose of prednisone; (b) Chinese medicine formula DSQRL; (c) combined treatment of the above two; or (d) tap water of the same volume. At the end of 30 days treatment, the DSQRL treatment achieved a better outcome (p<0.05) than prednisone in terms of histological examination, bronchoalveolar lavage fluid analysis, hydroxyproline assay and complications. The observations support further investigation and clinical trials of this Chinese medicinal formula for the treatment of PF.

Animals↗

PubMed1996

Substance P-like immunoreactive substance in bronchoalveolar lavage fluids from patients with idiopathic pulmonary fibrosis and pulmonary sarcoidosis.

In order to find out whether substance P (SP) participates in the inflammatory and fibrotic processes of interstitial lung diseases or not, SP-like immunoreactive substance (SP-IS) concentrations in bronchoalveolar lavage (BAL) fluids from patients with idiopathic pulmonary fibrosis (IPF) and pulmonary sarcoidosis were measured using enzyme immunoassay (EIA). The mean SP-IS concentrations in BAL fluids from healthy nonsmokers and healthy smokers were 0.87 +/- 0.19 and 0.98 +/- 0.23 pg/ml, respectively. The mean SP-IS concentration in BAL fluids from patients with IPF was 1.15 +/- 0.39 pg/ml. The value of patients with IPF was significantly higher than that of healthy nonsmokers (p < 0.01). The mean SP-IS concentrations in BAL fluids from pulmonary sarcoidosis patients in stage I, stage II and stage III were 0.91 +/- 0.19, 0.96 +/- 0.35 and 1.00 +/- 0.29 pg/ml, respectively. No correlation was found between SP-IS concentration and pulmonary functions in IPF and sarcoidosis patients. The present results indicate that SP may be involved in the inflammatory process in IPF.

Adult↗

PubMed1994

Soluble intercellular adhesion molecule-1 (ICAM-1) in sera and bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis and pulmonary sarcoidosis.

ICAM-1 plays an important role in inflammatory diseases. To assess level of soluble ICAM-1 in the circulation and inflamed lesions, we measured levels of soluble ICAM-1 in the circulation and bronchoalveolar lavage fluid (BALF) of patients with idiopathic pulmonary fibrosis (IPF) and with pulmonary sarcoidosis (PS) and of healthy volunteers (HV), and we also analysed ICAM-1 expression of BALF cells in some patients and HV. IPF patients had significantly higher levels of circulating ICAM-1 than HV, while PS patients did not. By contrast, significantly increased levels of BALF soluble ICAM-1 were found in PS patients compared with those of HV, but not in IPF patients. There were no significant differences in the proportions of ICAM-1+ BALF lymphocytes in IPF patients, PS patients and HV, whereas significantly increased proportions of ICAM-1+ pulmonary alveolar macrophages were found in PS patients compared with those of HV, but not in IPF patients. There was a significant positive correlation of BALF soluble ICAM-1 levels to BALF lymphocyte proportions in PS patients. Although the source of BALF soluble ICAM-1 is unclear, BALF soluble ICAM-1 appears to reflect the grade of local activity of sarcoidosis. An interesting discrepancy between soluble ICAM-1 levels in the circulation and BALF was found in IPF patients, and this might be an important clue to an understanding of this disorder.

Adolescent↗