PubMed Health⌕ Search

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 253 records · Page 14Linked to original sources

Global analysis of gene expression in pulmonary fibrosis reveals distinct programs regulating lung inflammation and fibrosis.

The molecular mechanisms of pulmonary fibrosis are poorly understood. We have used oligonucleotide arrays to analyze the gene expression programs that underlie pulmonary fibrosis in response to bleomycin, a drug that causes lung inflammation and fibrosis, in two strains of susceptible mice (129 and C57BL/6). We then compared the gene expression patterns in these mice with 129 mice carrying a null mutation in the epithelial-restricted integrin beta6 subunit (beta6(-/-)), which develop inflammation but are protected from pulmonary fibrosis. Cluster analysis identified two distinct groups of genes involved in the inflammatory and fibrotic responses. Analysis of gene expression at multiple time points after bleomycin administration revealed sequential induction of subsets of genes that characterize each response. The availability of this comprehensive data set should accelerate the development of more effective strategies for intervention at the various stages in the development of fibrotic diseases of the lungs and other organs.

Animals↗

Adenosine-dependent pulmonary fibrosis in adenosine deaminase-deficient mice.

Pulmonary fibrosis is a common feature of numerous lung disorders, including interstitial lung diseases, asthma, and chronic obstructive pulmonary disease. Despite the prevalence of pulmonary fibrosis, the molecular mechanisms governing inflammatory and fibroproliferative aspects of the disorder are not clear. Adenosine is a purine-signaling nucleoside that is generated in excess during cellular stress and damage. This signaling molecule has been implicated in the regulation of features of chronic lung disease; however, the impact of adenosine on pulmonary fibrosis is not well understood. The goal of this study was to explore the impact of endogenous adenosine elevations on pulmonary fibrosis. To accomplish this, adenosine deaminase (ADA)-deficient mice were treated with various levels of ADA enzyme replacement therapy to regulate endogenous adenosine levels in the lung. Maintaining ADA-deficient mice on low dosages of ADA enzyme therapy led to chronic elevations in lung adenosine levels that were associated with pulmonary inflammation, expression of profibrotic molecules, collagen deposition, and extreme alteration in airway structure. These features could be blocked by preventing elevations in lung adenosine. Furthermore, lowering lung adenosine levels after the establishment of pulmonary fibrosis resulted in a resolution of fibrosis. These findings demonstrate that chronic adenosine elevations are associated with pulmonary fibrosis in ADA-deficient mice and suggest that the adenosine functions as a profibrotic signal in the lung.

Adenosine↗

Inhibition of pulmonary fibrosis by the chemokine IP-10/CXCL10.

Pulmonary fibrosis is an enigmatic and devastating disease with few treatment options, now thought to result from abnormal wound healing in the lung in response to injury. We have previously noted a role for the chemokine interferon gamma-inducible protein of 10 kD (IP-10)/CXC chemokine ligand 10 in the regulation of cutaneous wound healing, and consequently investigated whether IP-10 regulates pulmonary fibrosis. We found that IP-10 is highly expressed in a mouse model of pulmonary fibrosis induced by bleomycin. IP-10-deficient mice exhibited increased pulmonary fibrosis after administration of bleomycin, suggesting that IP-10 limits the development of fibrosis in this model. Substantial fibroblast chemoattractant and proliferative activities were generated in the lung after bleomycin exposure. IP-10 significantly inhibited fibroblast responses to the chemotactic, but not the proliferative activity generated, suggesting that IP-10 may attenuate fibroblast accumulation in bleomycin-induced pulmonary fibrosis by limiting fibroblast migration. Consistent with this inhibitory activity of IP-10 on fibroblast migration, fibroblast accumulation in the lung after bleomycin exposure was dramatically increased in IP-10-deficient mice compared with wild-type mice. Conversely, transgenic mice overexpressing IP-10 were protected from mortality after bleomycin exposure, and demonstrated decreased fibroblast accumulation in the lung after challenge compared with wild-type mice. Our findings suggest that interruption of fibroblast recruitment may represent a novel therapeutic strategy for pulmonary fibrosis, which could have applicability to a wide range of fibrotic illnesses.

Animals↗

[Clinical, radiologic and functional changes in the respiratory system and changes in cytology of bronchoalveolar lavage fluid of patients with idiopathic pulmonary fibrosis].

The course of the pulmonary fibrosis is difficult to estimate as there are no diagnostic tests specific and sensitive enough to assess disease activity. Together 33 patients with pulmonary fibrosis have been studied. They have been divided into 2 subgroups, depending on the intensity of clinical, radiologic, and functional disorders. In all patients bronchoalveolar lavage has been carried out, and the obtained results have been compared with those in 18 healthy individuals. Changes in the cellular composition of BAL fluid had polymorphic character. In the early phase of the disease, only percentage of lymphocytes in BAL fluid has been increased significantly whereas in the more advanced stage percentage of both neutrophils and eosinophils has also been significantly increased. The use of several parameters simultaneously helps to evaluate pulmonary fibrosis.

Aged↗

Opposing regulatory roles of complement factor 5 in the development of bleomycin-induced pulmonary fibrosis.

The mechanisms of idiopathic pulmonary fibrosis pathogenesis, a chronic and progressive interstitial lung disease, remain elusive. The complement system, a crucial arm of the innate immune response, plays a pivotal role in several pathological disorders; however, the contribution of individual complement components to lung fibrosis has not yet been examined. Complement factor 5 (C5) and its cleavage product C5a are critical mediators in inflammatory diseases. Thus, to evaluate the role of C5 in lung fibrosis, we compared congenic C5-sufficient and C5-deficient mice in a well-characterized murine model of bleomycin-induced pulmonary fibrosis. C5-deficient mice had an exaggerated inflammatory phenotype compared with C5-sufficient mice during acute bleomycin-induced lung injury. These findings suggest a protective and anti-inflammatory role for C5, which was linked to the regulation of matrix metalloproteinases involved in cell migration. In contrast, C5 had a detrimental effect during chronic stages of bleomycin-induced injury, indicating a profibrotic role for C5. This deleterious activity for C5 was associated with expression of the fibrogenic cytokine TGF-beta1 and matrix metalloproteinase-3, an important mediator in fibroblast contraction. Altogether, our data reveal novel and opposing roles for C5 in both inflammation and tissue repair. Furthermore, these findings provide insight into the development of new therapeutic strategies for idiopathic pulmonary fibrosis patients.

Animals↗

Pulmonary fibrosis: cytokines in the balance.

Pulmonary fibrosis can complicate diverse pulmonary and systemic pathologies. In many cases the underlying cause remains unidentified. Mortality from the disease is increasing steadily in the UK and USA. The clinical features are well-described, but patients frequently present at an advanced stage, and current treatments have not improved the poor prognosis. There is a compelling need to identify the fibrotic process earlier and to develop new therapeutic agents. Increased collagen deposition is central to the pathology and interest over the last decade has focused on the role of cytokines in this process. These polypeptide mediators are believed to be released from both circulating inflammatory and resident lung cells in response to endothelial and epithelial injury. Key cytokines currently implicated in the fibrotic process are transforming growth factor-beta, tumour necrosis factor-alpha and endothelin-1. This article outlines the evidence implicating these mediators in the pathogenesis of pulmonary fibrosis and also considers the possible role of cytokines with antifibrotic effects, such as interferon-gamma. The "balance" of positively and negatively regulating cytokines is discussed, and the potential for interaction with other factors including viruses, hormones and altered antioxidant status is also considered. Finally, potential novel therapeutic approaches are discussed, together with suggestions for future studies and clinical trials. As the outcomes of different avenues of research over the last ten years are brought together, it is clear that there is now a hitherto unrivalled opportunity to begin to tackle the treatment of this devastating disease.

Animals↗

Bilirubin ameliorates bleomycin-induced pulmonary fibrosis in rats.

Many possible treatments for pulmonary fibrosis have been investigated, but except for some current clinical trials, none have succeeded in clinical trials. On the basis of the antioxidant action of bilirubin (BIL), we examined the effects of hyperbilirubinemia on the development of bleomycin (BLM)-induced pulmonary fibrosis in rats. The animals' plasma BIL level was kept within 3 and 10 mg/dl by repeated intravenous infusion of a high dose of BIL. We studied the inhibitory effects of hyperbilirubinemia on BLM-induced pulmonary fibrosis through histopathologic and biochemical analyses. Mortality of rats with BLM-induced pulmonary fibrosis was significantly lower in the three groups with hyperbilirubinemia. The ameliorating effect of hyperbilirubinemia on pulmonary fibrosis was shown by lung histology, as well as by a decreased lung content of hydroxyproline and reduced bronchoalveolar lavage fluid (BALF) concentration of transforming growth factor (TGF)-beta(1). The number of polymorphonuclear leukocytes and lymphocytes in BALF was also decreased in the groups with hyperbilirubinemia. Furthermore, oxidative metabolites of BIL in urine were present at significantly higher levels in BLM-treated rats with hyperbilirubinemia than in those without hyperbilirubinemia. These data suggest that the antioxidative action of BIL can attenuate BLM-induced pulmonary fibrosis, partly by inhibiting lung inflammation and production of TGF-beta1.

Animals↗

A p38 MAPK inhibitor, FR-167653, ameliorates murine bleomycin-induced pulmonary fibrosis.

To elucidate the pathophysiology of pulmonary fibrosis, we investigated the involvement of p38 mitogen-activated protein kinase (MAPK), which is one of the major signal transduction pathways of proinflammatory cytokines, in a murine model of bleomycin-induced lung fibrosis. p38 MAPK and its substrate, activating transcription factor (ATF)-2, in bronchoalveolar lavage fluid cells were phosphorylated by intratracheal exposure of bleomycin, and the phosphorylation of ATF-2 was inhibited by subcutaneous administration of a specific inhibitor of p38 MAPK, FR-167653. FR-167653 also inhibited augmented expression of tumor necrosis factor -alpha, connective tissue growth factor, and apoptosis of lung cells induced by bleomycin administration. Moreover, daily subcutaneous administration of FR-167653 (from 1 day before to 14 days after bleomycin administration) ameliorated pulmonary fibrosis and pulmonary cachexia induced by bleomycin. These findings demonstrated that p38 MAPK is involved in bleomycin-induced pulmonary fibrosis, and its inhibitor, FR-167653, may be a feasible therapeutic agent.

Activating Transcription Factor 2↗

Role of vagal airway reflexes in control of ventilation in pulmonary fibrosis.

1. In 10 patients with pulmonary fibrosis and in seven control subjects, we measured the pressure at the mouth 0 . 1 s after onset of an inspiration against occluded airway (P 0 . 1), minute ventilation (VI), breathing frequency (fr), tidal volume (VT), inspiratory duration (Ti) and calculated the mean inspiratory flow (VT/Ti) and the fraction of the breath cycle devoted to inspiration (Ti/T tot.). In the patients measurements were made at normal arterial oxygen saturations (SaO2), before and after lignocaine airway anaesthesia. 2. Efficacy of airway anaesthesia was tested by the cough response to citric acid inhalation. 3. In pulmonary fibrosis P 0 . 1, f1 and VT/Ti were greater than in the control subjects, VT and Ti were smaller and Ti/T tot. and VI were not different. 4. Effective airway anaesthesia did not modify P 0 . 1 and breathing pattern parameters observed in pulmonary fibrosis. 5. These results suggest that airway receptors do not contribute to a major extent to the control of breathing in pulmonary fibrosis.

Adult↗

Incidence and recognition of interstitial pulmonary fibrosis in developing countries.

Interstitial pulmonary fibrosis in developing countries is now diagnosed with an increased frequency. Increased awareness and more frequent availability of computed tomography and fiberoptic bronchoendoscopy have helped in making the diagnosis more often. The spectrum of diseases causing pulmonary fibrosis is broadly similar to that seen in the West. Connective tissue disorders such as systemic sclerosis and rheumatoid arthritis and sarcoidosis are more common causes. Idiopathic fibrosis is seen in approximately half the patients. Pneumoconiosis such as silicosis are also important. Diagnosis is often established on the basis of clinical features and radiologic findings alone. Transbronchial lung biopsy is used as a frequent method to make histologic diagnosis. Some of the causes described from India are rather rare. One of the interesting examples included a patient in whom pulmonary fibrosis was related to his ascent to very high altitude. Extreme cold, solar radiation, and other factors complicating low atmospheric oxygen pressure were implicated as causative factors. Lung fibrosis, secondary to exposure to toxic gas (methyl isocyanate), is reported in survivors of the Bhopal gas leakage tragedy of 1984. Serial bronchoalveolar studies have show elevated fibronectin levels and the presence of macrophage-neutrophilic exudate in the lavage fluid.

Developing Countries↗

A comparative study of the role of erythropoietin in the pathogenesis of deficient erythropoiesis in idiopathic pulmonary fibrosis as opposed to chronic obstructive pulmonary disease.

BACKGROUND: Despite the severe derangement of gas exchange in the advanced stages of idiopathic pulmonary fibrosis (IPF), secondary erythrocytosis is either absent or much lower than is seen in chronic obstructive pulmonary disease (COPD) with comparable hypoxemia. This study investigates the differences in erythropoiesis between IPF and COPD, searching for the possible underlying mechanisms. MATERIAL/METHODS: The study included 32 patients with COPD, 18 patients with IPF, all with overt hypoxemia (PO(2) <65 mmHg), and 34 healthy controls. Erythrocytic parameters and serum erythropoietin (EPO) levels were assessed for all subjects. In a number of patients from both groups, the development of erythroid colonies grown from peripheral blood mononuclear cells was assayed in semisolid methylcellulose cultures and compared to cultures of control cells, in the presence of patient or control serum. RESULTS: Hb and serum EPO levels were significantly higher in the COPD group than in IPF patients and controls. However, the number of BFU-E colonies obtained from mononuclear cells of IPF patients was clearly higher than in COPD patients when the same culture medium was used. Unlike COPD sera, IPF sera induced a significant growth inhibition of erythroid bursts arising from mononuclear cells of both patients and controls. CONCLUSIONS: Our findings suggest a kind of ineffective erythropoiesis in IPF. Defective EPO production and inhibitory effect on erythropoiesis exerted by pro-inflammatory cytokines released from alveolar macrophages may be implicated in the suboptimal erythropoietic response. However, the possible involvement of other factors affecting erythropoiesis in IPF requires further investigation.

Aged↗

Pulmonary tuberculosis in patients with idiopathic pulmonary fibrosis.

OBJECTIVES: Patients with idiopathic pulmonary fibrosis (IPF) have an increased risk of pulmonary tuberculosis. However, detecting pulmonary tuberculosis may be difficult due to the underlying fibrosis. The aim of this report is to describe the radiological and clinical findings of pulmonary tuberculosis in patients with idiopathic pulmonary fibrosis. MATERIALS AND METHODS: We reviewed 143 consecutive patients in whom IPF was diagnosed by either the histological or radio-clinical criteria. Among them, nine patients were histologically (n=2) or bacteriologically (n=7) confirmed to have active pulmonary tuberculosis. The location and patterns of pulmonary tuberculosis were examined on a thin section CT scan. RESULTS: The most common thin section CT findings were subpleural nodules (n=6; mean diameter, 3.2 cm) and a lobar or segmental consolidation (n=3). The lesions were located most commonly in the right lower lobe (n=4). The incidence of tuberculosis in patients with idiopathic pulmonary fibrosis was more than five times higher than that of the general population. CONCLUSION: The atypical manifestation of pulmonary tuberculosis is common in patients with idiopathic pulmonary fibrosis, which may mimic lung cancer or bacterial pneumonia.

Aged↗

The role of the Th2 CC chemokine ligand CCL17 in pulmonary fibrosis.

Increasing evidence suggests that the development of pulmonary fibrosis is a Th2-mediated process. We hypothesized that the CC chemokines that are associated with a Th2 profile (CCL17 and CCL22) have an important role in the development of pulmonary fibrosis. We measured CCL17 and CCL22 during the pathogenesis of bleomycin-induced pulmonary fibrosis. We found that both CCL17 and CCL22 were significantly elevated through day 20 as compared with control mice. Peak expression of CCL22 preceded the peak levels of CCL17, as measured by real-time quantitative PCR. CCR4 is the receptor for CCL17 and CCL22 therefore, to further characterize the role of CCL17 and CCL22, we measured CCR4 mRNA in lung tissue of bleomycin-treated mice by real-time quantitative PCR. CCR4 was significantly elevated in bleomycin-treated mice as compared with control mice. Immunolocalization demonstrated that CCR4 was expressed predominantly on macrophages. Neutralization of CCL17, but not CCL22, led to a reduction in pulmonary fibrosis. Immunolocalization of bleomycin-treated lung tissue and human idiopathic pulmonary fibrosis tissue specimens showed that epithelial cells expressed CCL17. These findings demonstrate a central role for Th2 chemokines and the macrophage in the pathogenesis of pulmonary fibrosis and are further support for the role of a Th2 phenotype in the pathogenesis of pulmonary fibrosis.

Animals↗

Unravelling the transcriptomic characteristics of bronchoalveolar lavage in post-covid pulmonary fibrosis.

BACKGROUND: Post-Covid Pulmonary Fibrosis (PCPF) has emerged as a significant global issue associated with a poor quality of life and significant morbidity. Currently, our understanding of the molecular pathways of PCPF is limited. Hence, in this study, we performed whole transcriptome sequencing of the RNA isolated from the bronchoalveolar lavage (BAL) samples of PCPF and compared it with idiopathic pulmonary fibrosis (IPF) and non-ILD (Interstitial Lung Disease) control to understand the gene expression profile and associated pathways. METHODS: BAL samples from PCPF (n&#x2009;=&#x2009;3), IPF (n&#x2009;=&#x2009;3), and non-ILD Control (n&#x2009;=&#x2009;3) (individuals with apparent healthy lung without interstitial lung disease) groups were obtained and RNA were isolated for whole transcriptomic sequencing. Differentially Expressed Genes (DEGs) were determined followed by functional enrichment analysis and qPCR validation. RESULTS: A panel of differentially expressed genes were identified in bronchoalveolar lavage fluid cells (BALF) of PCPF as compare to control and IPF. Our analysis revealed dysregulated pathways associated with cell cycle regulation, immune responses, and neuroinflammatory processes. Real-time validation further supported these findings. The PPI network and module analysis shed light on potential biomarkers and underscore the complex interplay of molecular mechanisms in PCPF. The comparison of PCPF and IPF identified a significant downregulation of pathways that were more prominent in IPF. CONCLUSION: This investigation provides crucial insights into the molecular mechanism of PCPF and also outlines avenues for prospective research and the development of therapeutic approaches.

Humans↗