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)

Bleomycin (BLM) is a very effective antineoplastic drug for many gynecologic and urinary tract carcinomas. However, its use, e.g., cumulative dosage, often is limited by the pulmonary fibrosis that it causes. The mechanism by which BLM causes fibrosis is not understood but is proposed to involve the pulmonary macrophage, a central cell in the cytokine network of the lung. To examine the direct effects of this drug on the human alveolar macrophage, we have treated human alveolar macrophages (isolated from normal subjects by bronchoalveolar lavage) with BLM in vitro and examined resultant macrophage secretory products that have importance for inflammatory and fibrotic processes. A 24-h treatment with BLM (0.5-100 mU/ml) was found to result in 1) a concentration-dependent decrease in the ability of the macrophage to produce superoxide anion in response to phorbol 12,13-dibutyrate, 2) an increase in secreted interleukin-1 beta (IL-1 beta), and 3) a decrease in intracellular levels of adenosine 3',5'-cyclic monophosphate. Kinetic studies revealed a time-dependent appearance of BLM-induced cytokines; tumor necrosis factor-alpha could be detected as early as 4 h after stimulation, followed by IL-1 beta at 8 h. The secretion of these cytokines was found to precede the release of prostaglandin E2, which became significant only at 24 h. Taken together, the present results imply that the human alveolar macrophage does not contribute to BLM-induced oxidant injury of the lung but that it may contribute to the development of BLM-induced pulmonary fibrosis.
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PMID:Bleomycin stimulation of cytokine secretion by the human alveolar macrophage. 137 69

Interstitial pneumonia has been reported to be a side effect of treatment with interferon, and Sho-saiko-to (Xiao-Chai-Hu-Tang) may enhance this side effect. It is well known that activated neutrophils are important mediators of pulmonary fibrosis, so we studied the effects of interferon and Sho-saiko-to on neutrophil activation. Homogenized lung myeloperoxidase (MPO) activity was assayed after intraperitoneal injection of interferon with or without pretreatment with Sho-saiko-to. Although Sho-saiko-to alone did not change the lung MPO content, MPO in the lung was significantly increased by interferon administration. The increase was enhanced further by pretreatment with Sho-saiko-to. When the accumulated neutrophils are activated by some cytokines, such as TNF alpha or IL-1 beta from monocytes/macrophages, they may damage lung tissue. We therefore studied the effects of Sho-saiko-to and interferon on TNF alpha production in freshly isolated human monocytes. Sho-saiko-to increased the production of TNF alpha, but interferon did not. In addition, Sho-saiko-to significantly increased the production of TNF alpha by monocytes stimulated by lipopolysaccharide. Taken together, these data indicate that interferon causes neutrophils to accumulate in the lung. Sho-saiko-to alone may not injure lung tissue, but it increases the effect of interferon. When stimulated by some antigen, Sho-saiko-to may overstimulate the neutrophils. Granulocytes elastase and oxygen radicals released from activated neutrophils may damage lung tissue. The fibroblasts that repair the damaged tissue may increase the risk of pulmonary fibrosis.
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PMID:[A possible mechanism of interstitial pneumonia during interferon therapy with sho-saiko-to]. 754 Jun 98

Fibroblasts are the primary proliferating cell type in pulmonary fibrosis. We previously showed that inorganic, fibrogenic particles alter the platelet-derived growth factor (PDGF) receptor system on rat lung fibroblasts (Bonner, J. C., et al. 1993, J. Clin. Invest 92:425-430). In lung fibroblasts, PDGF is the most potent proliferative cytokine, and the responses to PDGF isoforms depend on the relative amounts of two PDGF receptors (PDGF-R alpha and PDGF-R beta). Interleukin 1 beta (IL-1 beta) production by lung macrophages is increased following exposure to fibrogenic particles. We have examined the role of IL-1 beta in regulating the lung fibroblast PDGF receptor system. IL-1 beta induced a 10-fold increase in the number of binding sites for [125I]PDGF-AA, caused a 2-fold increase in affinity of [125I]PDGF-AB, but it had no effect on [125I]PDGF-BB binding. PDGF-R alpha gene expression was increased 5-fold after 4 h of IL-1 beta treatment. IL-1 beta increased the proliferative and chemotactic response to PDGF isoforms in the following order of potency: AA > AB > BB. IL-1 beta was tested for its ability to cause increased [125I]PDGF-AA binding when complexed to its binding protein, alpha 2-macroglobulin (alpha 2M). IL-1 beta bound covalently to fast methyl-amine-activated alpha 2M (alpha 2M-MA). IL-1 beta-alpha 2M-MA or alpha 2M-MA alone possessed minimal activity for inducing an increase in [125I]PDGF-AA binding. However, treatment of the IL-1 beta-alpha 2M complex with thioredoxin, which released bioactive IL-1 beta that was covalently bound to alpha 2M, maximally increased [125I]PDGF-AA binding to the same extent as free IL-1 beta. These results indicate that the fibroblast response to PDGF isoforms is modulated by a complex interaction involving IL-1 beta, alpha 2M, and thioredoxin, all of which are produced in vivo by activated macrophages.
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PMID:Interleukin 1 beta (IL-1 beta) and the IL-1 beta-alpha 2-macroglobulin complex upregulate the platelet-derived growth factor alpha-receptor on rat pulmonary fibroblasts. 754 76

IL-1 is a key cytokine that promotes pulmonary inflammation and fibrosis, as a result of its ability to stimulate lung fibroblast proliferation and collagen synthesis, two hallmarks of fibrosis. The IL-1 receptor antagonist (IL-1Ra) is an important natural inhibitor of IL-1-mediated functions. In models of pulmonary fibrosis induced by chemotherapeutic agents or noxious particles, administration of IL-1Ra significantly ameliorates lung fibrosis. Lung tissue undergoing an inflammatory response shows elevations in IL-1Ra, although it is not clear which pulmonary cells are responsible for the IL-1Ra synthesis. The purpose of this research was to determine whether Thy-1+ and Thy-1- subsets of mouse lung fibroblasts were capable of synthesizing IL-1Ra. In this report, it is demonstrated for the first time that lung fibroblasts are capable of synthesizing IL-1Ra. Both Thy-1+ and Thy-1- parental lines and clones constitutively express IL-1Ra mRNA. Quantitation of IL-1Ra protein indicates that Thy-1+ and Thy-1- fibroblasts secrete similar levels of secreted but not intracellular IL-1Ra. Thy-1- fibroblasts accumulate higher levels of IL-1Ra intracellularly. Moreover, fibroblast-conditioned supernatants containing IL-1Ra significantly suppress the mitogenic response of a T cell clone, D10G4.1, to concanavalin A and IL-1 beta. Overall, our observations indicate that Thy-1+ and Thy-1- fibroblasts release IL-1Ra and possess an IL-1-specific inhibitory activity in their supernatants. In vivo, fibroblast-derived IL-1Ra may serve to regulate IL-1-mediated effects in an autocrine and/or paracrine fashion to maintain homeostasis in the pulmonary interstitium.
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PMID:Synthesis of interleukin-1 receptor antagonist by Thy-1+ and Thy-1- murine lung fibroblast subsets. 764 35

In order to clarify the mechanisms of pulmonary fibrosis, we produced bleomycin (BLM)-induced pulmonary fibrosis in rats and examined the ability of alveolar macrophages (AM) to produce interleukin-1 (IL-1). BLM (0.9 mg) was administered once via the trachea to male Wistar rats weighing about 200 g. Bronchoalveolar lavage was performed at 1, 3, 6, 9 and 12 days after administration. AM were incubated for 24 hours, then extracellular IL-1 in the supernatants and cell-associated IL-1 of AM were measured by proliferation assay of mouse thymocytes. Cell-associated IL-1 activity was measured after fixation by paraformaldehyde (PFA). Extracellular IL-1 was detected in the culture media of AM at only day 1 after administration. On the other hand, cell-associated IL-1 was detected in AM fixed by PFA on days 1, 3, 6 and 9 after administration. AM from BLM-induced pulmonary fibrosis in rats were fixed by PFA and then were treated with anti-IL-1 alpha antibody or anti-IL-1 beta antibody. Cell-associated IL-1 activity was neutralized by treatment with anti-IL-1 alpha antibody and was not neutralized by treatment with anti-IL-1 beta antibody. Following this, the effect of cell-associated IL-1 on pulmonary fibroblasts was examined. This was estimated by the proliferation of pulmonary fibroblasts using incorporation of 3H-thymidine. When pulmonary fibroblasts were incubated with AM fixed by PFA from BLM-induced pulmonary fibrosis in rats, proliferation of pulmonary fibroblasts was inhibited.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Cell-associated interleukin 1 production of alveolar macrophages from bleomycin-induced pulmonary fibrosis in rats]. 769 78

Susceptibility of mice to the induction of pulmonary fibrosis by bleomycin sulfate is inbred strain dependent, with C57BL/6 mice exhibiting high sensitivity to the drug and BALB/c mice demonstrating a resistant phenotype. The lungs of bleomycin treated C57BL/6J and BALB/cBy mice were analyzed for their mRNA expression level of a panel of cytokines using a semi-quantitative polymerase chain reaction (SQ-PCR) assay. Transforming growth factor-beta 1 (TGF-beta 1) mRNA was found to increase sevenfold by 5 days after bleomycin treatment of C57BL/6J (sensitive) mice. BALB/cBy (resistant) animals demonstrated a lower level of TGF-beta 1 mRNA induction, approximately threefold, after bleomycin administration. Analysis of interleukin-1 beta (IL-1 beta) mRNA levels also revealed a difference between the two strains, with BALB/cBy mice expressing approximately fourfold higher IL-1 beta mRNA levels than C57BL/6J mice. This result suggested possible protection by IL-1 beta. Analysis of (C57BL/6JxBALB/cBy)F1 hybrids, which are shown in this report to be sensitive to bleomycin-induced fibrosis, revealed a high IL-1 beta mRNA level, similar to that in the resistant parent. Thus, the observed strain variation in the level of IL-1 beta mRNA is not associated with differences in susceptibility to the induction of pulmonary fibrosis. In contrast, strain variation in interleukin-6 (IL-6) mRNA levels was observed that was completely concordant with the segregation of susceptibility phenotypes between the parental and F1 strains. This result indicates a possible association between sensitivity to bleomycin-induced fibrosis and inducibility of IL-6 mRNA upon drug treatment. Analysis of TGF-beta 2, interferon-gamma, interleukin-2, interleukin-3, and interleukin-4 (IL-4) mRNA showed no detectable strain variation in steady state mRNA levels in the lung as a consequence of bleomycin treatment. In contrast, the level of IL-4 receptor mRNA was induced to a higher degree in both sensitive groups (C57BL/6J and F1) than in resistant mice (BALB/cBy). Therefore, modulation of the IL-4 response, not at the level of IL-4 but through regulation of the IL-4 receptor, may play a role in pulmonary fibrogenesis.
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PMID:PCR analysis of cytokine induction profiles associated with mouse strain variation in susceptibility to pulmonary fibrosis. 769 32

We measured levels of cytokines and type III procollagen aminopeptides (procollagen III peptides) in bronchoalveolar lavage fluid obtained from 20 patients with stable pulmonary fibrosis (PF) and seven patients with progressive PF, and nine control subjects to determine the role of cytokines in the development of PF. Procollagen III peptide levels were markedly increased in progressive PF patients. Tumour necrosis factor-alpha, interleukin-6, transforming growth factor-beta and interferon-gamma (IFN-gamma) levels were elevated in both PF patients as compared with controls, with a tendency of higher levels in progressive patients, whereas interleukin-1 beta (IL-1 beta) level was decreased in both PF patients. When the correlation between procollagen III peptide and various cytokine levels was analysed the only significant correlation was inversely between procollagen III peptide and IFN-gamma in progressive PF patients. These results indicated that although multiple cytokines may be involved in the development of PF, the negative role of IFN-gamma in active collagen synthesis could be also important.
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PMID:Determination of various cytokines and type III procollagen aminopeptide levels in bronchoalveolar lavage fluid of the patients with pulmonary fibrosis: inverse correlation between type III procollagen aminopeptide and interferon-gamma in progressive patients. 788 35

Studies have indicated that soluble products, including chemotactic factors, released by activated lung macrophages and fibroblasts are critical mediators in the pathogenesis of asbestos-induced pulmonary fibrosis. We provide evidence that mediators produced by lung epithelial cells in response to asbestos may also contribute to lung disease. In the present study, the carcinogenic and fibrogenic fibers, chrysotile and crocidolite asbestos, were shown to directly stimulate the human pulmonary type-II epithelial cell line, A549, and to a lesser degree primary human bronchial epithelial cells, to elicit the chemotactic cytokine IL-8 in the absence of endogenous stimuli such as IL-1 and TNF. That the membrane signaling events responsible for asbestos-induced IL-8 production are distinct from those responsible for IL-8 induction by cytokines was confirmed by using membrane-stabilizing agents and protein synthesis inhibitors. Stimulation was not observed with nonfibrogenic fibers, wollastonite and titanium dioxide, and was the direct result of asbestos-induced initiation of transcription. Asbestos failed to stimulate the release of TNF, IL-1 beta, or monocyte chemoattractant protein-1 in A549 or primary bronchial epithelial cells, indicating that cytokine secretion by asbestos is highly selective. However, a slight release of IL-1 alpha, probably preformed, was released in human bronchial epithelial cells. These data suggest that epithelial cells may, in addition to macrophages and fibroblasts, be an important effector cell in the immunopathogenesis of asbestos-associated diseases and in particular, in the neutrophilic infiltration that is commonly observed after asbestos exposure.
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PMID:Asbestos stimulates IL-8 production from human lung epithelial cells. 808 96

Therapeutic thoracic irradiation may induce two late pulmonary injury syndromes: radiation pneumonitis and subsequent pulmonary fibrosis. The alveolar macrophage has been considered a radioresistant cell and not a target cell involved in the pathogenesis of either type of radiation-induced lung injury. Alveolar macrophage-derived cytokines, including interleukin-1 (IL-1) and tumor necrosis factor (TNF), have been demonstrated to participate in inflammatory and fibrotic responses in the lung after various other types of lung injury. To evaluate whether the release of cytokines by alveolar macrophages is induced by radiation doses used clinically, alveolar macrophages recovered from nonsmoking volunteers were exposed in vitro to a single dose of 2 Gy and then maintained in culture for 18 h. Culture supernatants and cell lysates were then recovered and analyzed for IL-1 alpha and IL-1 beta by radioimmunoassay. Supernatants of irradiated alveolar macrophages contained significantly increased amounts of IL-1 alpha (P < 0.04) and IL-1 beta (P < 0.02) as well as total IL-1 (IL-1 alpha and IL-1 beta) (P < 0.02) compared to nonirradiated alveolar macrophages. Cell lysates of irradiated alveolar macrophages also contained increased amounts of IL-1 alpha and IL-1 beta, although differences from controls were not significant. The finding of increased release of IL-1 by alveolar macrophages after exposure to a single, clinically relevant dose of radiation suggests that the function of human alveolar macrophages is likely altered during therapeutic use of thoracic irradiation. Whether this release of IL-1 by alveolar macrophages contributes to early lung inflammation induced by thoracic irradiation is unclear.
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PMID:Release of interleukin-1 by human alveolar macrophages after in vitro irradiation. 821 Mar 36

The lung macrophage is proposed to be involved in the development of asbestos-induced pulmonary fibrosis. Knowledge of the effects of long-term asbestos exposure on lung macrophage cytokine release should better define the role of the macrophage in fibrogenesis. This study examines the effects of acute in vitro asbestos exposure and chronic in vivo asbestos exposure on human alveolar macrophage cytokine release. As indicators of asbestos-induced macrophage activation, the cellular release of IL-1 beta, TNF-alpha, IL-6, GM-CSF, and PGE2 was measured during a 24-h in vitro culture. Alveolar macrophages from normal volunteers were cultured in vitro with chrysotile asbestos. Of the factors measured, only TNF-alpha was elevated in response to asbestos exposure. Alveolar macrophages from asbestos-exposed individuals were placed into one of two groups based on their exposure history. These two groups were matched for age, smoking history, and diagnosis; none met the criteria for asbestosis. Cells isolated from subjects that had been exposed to asbestos for more than 10 years secreted enhanced basal amounts of IL-1 beta, TNF-alpha, IL-6, and PGE2, while those who had been exposed for less than 10 years did not. The results indicate that while asbestos had minimal acute effects on cytokine production by the human alveolar macrophage, intense, chronic exposure to asbestos leads to the enhanced basal release of significant amounts of several cytokines that have activity for the fibroblast, even in the absence of overt fibrosis.
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PMID:Human alveolar macrophage cytokine release in response to in vitro and in vivo asbestos exposure. 844 Feb 2


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