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PubMed2002

Future research directions in idiopathic pulmonary fibrosis: summary of a National Heart, Lung, and Blood Institute working group.

Idiopathic pulmonary fibrosis (IPF) is an insidious inflammatory fibroproliferative disease whose cause and course before diagnosis are unknown, and for which existing treatments are of limited benefit. The National Heart, Lung, and Blood Institute convened a working group to develop specific recommendations for future IPF research. Inflammatory and immune processes are involved in IPF pathogenesis, and current therapeutic strategies are aimed at suppressing the inflammation. Recent data suggest that the molecular processes underlying the fibrogenesis may provide new opportunities for therapeutic intervention. Specific areas of future research recommended by the working group include studies to elucidate the etiology of IPF, to develop novel diagnostic techniques and molecular diagnostics, to establish a program for identification of molecular targets for IPF treatment and identification and generation of agonists or antagonists that inhibit fibrogenesis, to foster investigations that couple the use of new technologies (e.g., laser capture microdissection, microarrays, and mass spectroscopic analysis of proteins) with data from the human genome project, to establish a national consortium of Clinical Centers of Excellence to conduct coordinated clinical and laboratory studies of well-characterized patients and patient-derived materials, and to stimulate research to develop animal models of persistent and progressive pulmonary fibrosis for evaluation of new intervention approaches.

Humans↗
PubMed1997

Lung function tests in patients with idiopathic pulmonary fibrosis. Are they helpful for predicting outcome?

STUDY OBJECTIVE: Idiopathic pulmonary fibrosis (IPF) varies widely in its course. To evaluate predictive parameters at presentation to the hospital, we investigated 99 patients with IPF (47 women), focusing on extensive lung function tests. METHODS: Standard tests of lung volumes, arterial oxygen tension, and gas exchange at rest and during bicycle exercise were performed. Survival rates in relation to functional parameters were calculated using the actuarial method. Differences in survival proportions were summarized as hazard ratios, and significance levels were determined by log-rank test. RESULTS: At presentation, most patients showed a reduced total lung capacity (TLC) of 79.2 +/- 21.1%, an arterial oxygen tension (PaO2) considered pathologic in 63%, when related to age, a significant decrease of PaO2 with 11.8 +/- 12.1 mm Hg and an increase of the alveolar-arterial oxygen pressure difference with 46.4 +/- 16.4 (12.2 to 76.8) mm Hg during bicycle exercise. Diminished survival was associated with an age older than 50 years, a reduced value to more than 2 SDs below the predicted values of both, TLC alone, or in combination with a reduced vital capacity. Factors not influencing survival were gender, parameters of gas exchange at rest, and PaO2 at rest and during bicycle exercise. CONCLUSIONS: We conclude that standard lung function tests make it possible to assess the prognosis of patients with IPF, while extensive tests like gas exchange measurements at rest and during bicycle exercise do not contribute additional information to make the prognostic estimations more precise.

Exercise Test↗
PubMed2005

The absence of reactive oxygen species production protects mice against bleomycin-induced pulmonary fibrosis.

BACKGROUND: Reactive oxygen species and tissue remodeling regulators, such as metalloproteinases (MMPs) and their inhibitors (TIMPs), are thought to be involved in the development of pulmonary fibrosis. We investigated these factors in the fibrotic response to bleomycin of p47phox -/- (KO) mice, deficient for ROS production through the NADPH-oxidase pathway. METHODS: Mice are administered by intranasal instillation of 0.1 mg bleomycin. Either 24 h or 14 days after, mice were anesthetized and underwent either bronchoalveolar lavage (BAL) or lung removal. RESULTS: BAL cells from bleomycin treated WT mice showed enhanced ROS production after PMA stimulation, whereas no change was observed with BAL cells from p47phox -/- mice. At day 1, the bleomycin-induced acute inflammatory response (increased neutrophil count and MMP-9 activity in the BAL fluid) was strikingly greater in KO than wild-type (WT) mice, while IL-6 levels increased significantly more in the latter. Hydroxyproline assays in the lung tissue 14 days after bleomycin administration revealed the absence of collagen deposition in the lungs of the KO mice, which had significantly lower hydroxyproline levels than the WT mice. The MMP-9/TIMP-1 ratio did not change at day 1 after bleomycin administration in WT mice, but increased significantly in the KO mice. By day 14, the ratio fell significantly from baseline in both strains, but more in the WT than KO strains. CONCLUSIONS: These results suggest that NADPH-oxidase-derived ROS are essential to the development of pulmonary fibrosis. The absence of collagen deposition in KO mice seems to be associated with an elevated MMP-9/TIMP-1 ratio in the lungs. This finding highlights the importance of metalloproteinases and protease/anti-protease imbalances in pulmonary fibrosis.

Animals↗
PubMed1997

Induction of apoptosis and pulmonary fibrosis in mice in response to ligation of Fas antigen.

Fas antigen is a cell surface protein that mediates apoptosis, and it is expressed in various cells and tissues. Fas ligand binds to its receptor Fas, thus inducing apoptosis of Fas-bearing cells. Malfunction of the Fas-Fas ligand system causes lymphoproliferative disorders and autoimmune diseases, whereas its exacerbation may cause tissue destruction. We hypothesize that excessive apoptosis mediated by Fas-Fas ligand interaction may damage alveolar epithelial cells and result in pulmonary fibrosis. Mice were allowed to inhale repeatedly an aerosolized anti-Fas antibody for 14 days. The nuclei of bronchial and alveolar epithelial cells were positively stained by in situ DNA nick end labeling. Electron microscopy demonstrated apoptotic changes in bronchial and alveolar epithelial cells. Histologic findings and hydroxyproline content showed the development of pulmonary fibrosis, which was dependent on the dose of anti-Fas antibody. The repeated inhalation of control antibody (isotype-matched control hamster IgG) did not induce apoptosis of epithelial cells or pulmonary fibrosis. The expression of TGF-beta mRNA was upregulated from day 7 to day 28 in lung tissues of anti-Fas antibody-treated mice but not in those of control mice. In this report, we present the evidence that repeated inhalation of anti-Fas antibody mimicking Fas-Fas ligand crosslinking induces excessive apoptosis and inflammation, which results in pulmonary fibrosis in mice.

Animals↗
PubMed1984

Interstitial pulmonary fibrosis induced in hamsters by intratracheally administered chrysotile asbestos. Histology, lung mechanics, and inflammatory events.

The development of interstitial pulmonary fibrosis (IPF) is associated with persistent cellular infiltration and progressive connective tissue accumulation in the alveolar walls. To develop and characterize an animal model of IPF in which pulmonary fibrosis evolves slowly, as well as to develop an inexpensive, easily produced, model of asbestosis, Syrian golden hamsters received single intratracheal injections of either UICC chrysotile asbestos or saline. Animals were then examined at time points up to 180 days for pulmonary histologic and physiologic changes, cytologic characteristics of cells recovered by bronchoalveolar lavage, and spontaneous release of neutrophil chemoattractant activity by alveolar macrophages. Within days after asbestos treatment, hamsters developed a patchy bronchopneumonia centered around terminal airways, which progressed peripherally with time to involve the alveolar walls with persistent inflammation and the gradual development of interstitial and peribronchiolar fibrosis. These histologic changes were accompanied by physiologic findings of air-flow obstruction with air trapping. Bronchoalveolar lavage revealed a persistent neutrophilia that began within 24 h of asbestos treatment; this was associated with the spontaneous release of neutrophil chemotactic activity by cultured alveolar macrophages. In this animal model, pulmonary inflammation and fibrosis can be predictably produced by a single intratracheal instillation of chrysotile asbestos. It represents a useful tool for studying both asbestosis and pulmonary fibrosis in general.

Animals↗
PubMed1999

[Perspectives for treatment of pulmonary fibrosis].

Conventional therapy of fibrogenic lung diseases, based mainly on the use of glucocorticoids or immunosuppressive, cytotoxic agents, does not usually protect before progression of disease and accumulation of the excess connective tissue in lungs. This article is a review of potential new therapies in the treatment of pulmonary fibrosis. Novel therapies emerged from the use of animal models of pulmonary fibrosis and recent advances in the cellular and molecular biology of inflammatory reaction involve the use of substances directed against the action of pathogenic agents: growth factors, cytokines or oxidants. Thus, future therapeutic strategies will be aimed at more selective and effective methods of controlling the key elements of pulmonary fibrosis.

Animals↗
PubMed2006

Doxycycline attenuated pulmonary fibrosis induced by bleomycin in mice.

The administration of doxycycline prior to bleomycin in mice attenuated pulmonary fibrosis. Bronchoalveolar neutrophil influx and gelatinase activity, but not caseinolytic activity, were attenuated by doxycycline. Established fibrosis was not affected by doxycycline. Thus, doxycycline might be useful for slowing down pulmonary fibrosis by biological activity other than antibacterial activity.

Animals↗
PubMed2003

Defect of hepatocyte growth factor secretion by fibroblasts in idiopathic pulmonary fibrosis.

Hepatocyte growth factor (HGF) is a growth factor that protects alveolar epithelial cells from pulmonary fibrosis in various animal models. We compared in vitro HGF production by human lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF, n = 8) and from control subjects (n = 6). Basal HGF secretion by IPF fibroblasts was decreased by 50% when compared with control fibroblasts (p < 0.05). HGF was secreted mainly in the cleaved mature form, both in IPF and control fibroblasts. HGF messenger RNA levels were reduced in IPF fibroblasts. Prostaglandin (PG) E2 secretion by IPF fibroblasts was low when compared with control subjects (p < 0.05). After the addition of PGE2 (10-6 M) or dibutyryl cyclic AMP (10-3 M), HGF secretion by IPF fibroblasts reached the level of control subjects. Inhibition of PGE2 synthesis with indomethacin reduced HGF secretion by control fibroblasts but had no effect on IPF fibroblasts. HGF secretion by control fibroblasts was also slightly inhibited by transforming growth factor (TGF)-beta1 and stimulated by anti-TGF-beta antibody, whereas both agents had no effect on IPF fibroblasts. Our results demonstrate a defect in HGF production by IPF fibroblasts that seems secondary to a defect in PGE2 secretion.

Adult↗
PubMed2001

Pulmonary fibrosis is increased in mice carrying the factor V Leiden mutation following bleomycin injury.

Increased fibrin deposition following inflammatory lung injury has been proposed to facilitate the development of pulmonary fibrosis. Therefore, factors predisposing to thrombosis may affect the fibrotic response to injury. Activated protein C (aPC) resistance due to the factor V Leiden mutation (FvL) is a common genetic risk factor for vascular thrombosis. To examine the relationship between aPC resistance and the development of pulmonary fibrosis, lung inflammation was induced by bleomycin in mice carrying the FvL mutation. Three weeks following the instillation of 0.0375 U of bleomycin, the lungs of mice homozygous and heterozygous for FvL contained significantly more hydroxyproline (35 +/- 4 and 36 +/- 7 ug hydroxyproline/mg total protein, respectively) than wild-type mice (26 +/- 6 ug/mg protein, p <0.01 for both comparisons). These data demonstrate a strong relationship between aPC resistance and the pulmonary fibrosis that occurs following inflammatory lung injury.

Activated Protein C Resistance↗
PubMed1982

Bleomycin-induced pulmonary fibrosis in hamsters: effect of neutrophil depletion on lung collagen synthesis.

The development of pulmonary fibrosis in hamsters after the intratracheal instillation of bleomycin is attended by exudation of polymorphonuclear leukocytes (PMNs), but the function of these cells is unknown. In this study, we examined the effect of PMN depletion on lung collagen synthetic rate in bleomycin-treated hamsters. Antiserum to hamster PMNs was produced in rabbits and injected intraperitoneally into hamsters on the fourth through seventh days after intratracheal instillation of bleomycin or saline. Control animals received either normal rabbit serum (NRS) or no serum. Anti-PMN serum (APS) significantly reduced PMN exudation after bleomycin treatment through the eighth day (p less than 0.01). Collagen synthetic rate measured in lung explant cultures was increased in all bleomycin-treated groups compared with that in the saline injected control group (p less than 0.005). Collagen synthesis was greater in neutrophil-depleted bleomycin-treated hamsters than in bleomycin-treated animals receiving NRS or no serum on Days 8 (p less than 0.01) and 12 (p less than 0.05). In APS-treated hamsters, the proportion of protein synthesis directed toward collagen synthesis was increased above other bleomycin-treated groups, suggesting that collagen synthesis is selectively increased in neutrophil-depleted hamsters with bleomycin-induced pulmonary fibrosis.

Animals↗
PubMed2004

Erdosteine prevents bleomycin-induced pulmonary fibrosis in rats.

Oxidative stress plays an important role in the pathogenesis of idiopathic pulmonary fibrosis. Therefore, erdosteine, an antioxidant, is expected to have an inhibitor potential against the disease. Rats were given one dose of bleomycin in pulmonary fibrosis groups and saline in controls. The first dose of oral erdosteine (10 mg/kg/day) was given 2 days before the bleomycin injection to achieve the plateau level in blood and continued until killing. At day 14, fibrotic changes were evaluated, using Aschoft's criteria and lung hydroxyproline content. Bleomycin produced a fivefold increase in fibrosis score that was decreased by 87% by erdosteine (P>0.001) and almost twofold increases in hydroxyproline content which were completely prevented by erdosteine. Myeloperoxidase activities and MDA levels, which were significantly higher in the bleomycin group, were then significantly attenuated by erdosteine. These results revealed that oral erdosteine may prevent the development of acute pulmonary inflammation caused by bleomycin injection via the repression of neutrophil accumulation and lipid peroxidation, resulting in the inhibition of subsequent lung fibrosis.

Animals↗
PubMed2003

Therapeutic attenuation of pulmonary fibrosis via targeting of IL-4- and IL-13-responsive cells.

Severe forms of idiopathic interstitial pneumonia (IIP), such as usual interstitial pneumonia, can be impervious to modern steroid and immunosuppressive treatment regimens, thereby emphasizing the need for novel effective therapies. Consequently, research attention has been directed toward understanding the cytokine networks that may affect fibroblast activation and, hence, the progression of certain IIPs. This led us to investigate whether the specific targeting of resident lung cells responsive to IL-4 and IL-13 exerted a therapeutic effect in an experimental model of IIP, namely the bleomycin-induced model of pulmonary fibrosis. IL-4, IL-13, and their corresponding receptor subunits, IL-4Ralpha, IL-13Ralpha1, and IL-13Ralpha2, were maximally expressed at the mRNA and protein levels in whole lung samples on day 21 or 28 after an intratracheal bleomycin challenge. The intranasal administration of an IL-13 immunotoxin chimeric molecule (IL13-PE) from days 21-28, but not for 1-wk periods at earlier times, after bleomycin challenge had a significant therapeutic effect on histological and biochemical parameters of bleomycin-induced pulmonary fibrosis compared with the control group. The intranasal IL13-PE therapy significantly reduced the numbers of IL-4 and IL-13 receptor-positive mononuclear cells and macrophages and the levels of profibrotic cytokine and chemokine in the lungs of bleomycin-challenged mice on day 28. Thus, this study demonstrates that IL-4- and/or IL-13-binding cells are required for the maintenance of pulmonary fibrosis induced by bleomycin and highlights the importance of further investigation of antifibrotic therapeutics that target these cells during pulmonary fibrosis.

Administration, Intranasal↗
PubMed2000

Serum surfactant proteins A and D as prognostic factors in idiopathic pulmonary fibrosis and their relationship to disease extent.

Idiopathic pulmonary fibrosis (IPF) is a progressive, life-threatening, interstitial lung disease of unknown etiology. For optimal therapeutic management of IPF an accurate tool is required for discrimination between reversible and irreversible types of the disease. However, such noninvasive tools are few, and even with high-resolution computed tomography (HRCT), which is the most trusted method for doing so, the nature of the disease activity in IPF cannot always be accurately predicted. The aims of the present study were to assess the values of surfactant protein (SP)-A and SP-D in semiquantifying the extent of disease in IPF and in predicting deterioration in restrictive pulmonary function and survival over a follow-up period of 3-yr. SP-A and SP-D in sera were measured with enzyme-linked immunosorbent assays as previously described. Fifty-two IPF patients were studied to evaluate the association between serum SP-A and SP-D and disease extent on HRCT, deterioration in pulmonary function, and survival during 3 yr of follow-up. Both SP-A and SP-D concentrations were significantly correlated with the extent of alveolitis (a reversible change), whereas they did not correlate with the progression of fibrosis (an irreversible change). The SP-D concentration, unlike that of SP-A, was also related to the extent of parenchymal collapse and the rate of deterioration per year in pulmonary function. The concentrations of SP-A and SP-D in patients who died within 3 yr were significantly higher than in patients who were still alive after 3 yr. We propose that assays of SP-A and SP-D in sera from IPF patients are useful tools for understanding some pathologic characteristics of the disease, that SP-D may be a good predictive indicator of the rate of decline in pulmonary function, and that a combination of the assays for SP-A and SP-D may be helpful in predicting the outcome of patients with IPF.

Aged↗
PubMed1999

[Effects of the anti-LCAMs monoclonal antibodies on proliferation of pulmonary fibrosis in vitro].

OBJECTIVE: To explore the effects of the antibodies to LCAMs on proliferation of pulmonary fibroblast (L929 cell line). METHODS: Proliferation of fibroblasto and level of collagen production were determined by (3)H-TDR incorporation and ELISA. RESULTS: The supernate of AMs cultured with anti-LCAMs could inhibit the proliferation of fibroblast. The presence of anti-CD(11)B (125 microg/ml) could significantly inhibit the proliferation of fibroblast (P < 0.05), and reduce collagen secretion by 29.7%. When anti-CD(18) and anti-CD(54) at the concentration of 25 microg/ml, 5 microg/ml respectively, the inhibition rate of fibroblast proliferation differed from that in control group (P < 0.05). moreover combination of the two antibodies resulted in more significant inhibition effect than that seen by the two antibodies separately. CONCLUSIONS: The increased expression of CAMs on AM might play an important role in the pathogenesis of the pulmonary fibrosis and MAbs to CD(11)B/CD(18), CD(54) possess a potential regiment for intervention of pulmonary fibrosis.

Animals↗
PubMed2001

Lung interleukin-4 gene expression in a murine model of bleomycin-induced pulmonary fibrosis.

Interleukin-4 (IL-4) is known to activate mononuclear cells as well as fibroblasts, all of which are important in the pathogenesis of pulmonary fibrosis. To investigate the potential role of this cytokine, lung IL-4 expression was examined in a murine model of bleomycin-induced pulmonary fibrosis. Lung fibrosis was induced in CBA/J mice by endotracheal injection of bleomycin on day 0. On selected days after treatment, lungs were harvested for reverse transcriptase polymerase chain reaction (RT-PCR), Northern, in-situ hybridization and immunohistochemical analyses. RT-PCR and Northern analyses revealed significant increases in lung IL-4 mRNA content between days 3 and 14 after induction of lung injury, which decreased toward control level after day 21. Both in-situ hybridization and immunohistochemistry showed low or undetectable IL-4 expression in control lungs and in injured lungs before day 3 after bleomycin injection. There was however elevated expression in mononuclear cells and macrophages between days 3 and 14, localized to areas of active fibrosis. These results demonstrate that IL-4 is upregulated significantly in this model. They suggest a potential role for this cytokine in pulmonary fibrosis, perhaps via its ability to stimulate and amplify the inflammatory response, stimulate collagen synthesis in fibroblasts, and thus promote the progression to fibrosis and end stage lung disease.

Animals↗
PubMed2001

Outpatient inhaled nitric oxide in a patient with idiopathic pulmonary fibrosis: a bridge to lung transplantation.

Inhaled nitric oxide (INO) has been shown to improve oxygenation and decrease intrapulmonary shunt and pulmonary hypertension in various lung diseases. In this study we report a patient with end-stage idiopathic pulmonary fibrosis and pulmonary hypertension who received INO after coronary artery bypass surgery, with significant improvement in arterial oxygenation and pulmonary arterial pressure. Using a pulsing delivery system, the patient continued to receive outpatient INO for 30 months while waiting for lung transplantation. Exercise study and two-dimensional echocardiogram, after 3 months of inhaled NO, demonstrated continued benefits of INO for improvement of arterial oxygenation, pulmonary arterial pressure and exercise tolerance.

Administration, Inhalation↗