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PubMed2000

Prospective randomized comparison of thoracoscopic talc poudrage under local anesthesia versus bleomycin instillation for pleurodesis in malignant pleural effusions.

Induction of pleurodesis offers benefit for patients with metastatic tumors and symptomatic malignant pleural effusions, but the best method for achieving this is still unknown. In this prospective, randomized comparison of two well-established pleurodesis procedures, 36 patients with malignant pleural effusions, expanded lungs after drainage, and expected survival of > 1 mo received either bleomycin instillation (60E) via a small-bore thoracostomy tube or thoracoscopic talc poudrage (5 g) under local anesthesia. Efficacy, safety, and cost could be evaluated for 32 treatments (17 bleomycin, 15 talc) in 31 patients. Recurrence rates of effusion with bleomycin and talc poudrage after 30 d were 41% and 13% (p = 0.12), respectively, those after 90 d were 59% and 13%, respectively (p = 0.01), and those after 180 d were 65% and 13% (p = 0.005), respectively. Neither procedure showed any major adverse effect, and both were equally well tolerated. Cost estimation favored thoracoscopic talc poudrage, both for the initial hospitalization and with regard to recurrences. In conclusion, thoracoscopic talc pleurodesis under local anesthesia is superior to bleomycin instillation for pleurodesis in cases of malignant pleural effusion.

Aged↗
PubMed2001

Transient transgene expression of decorin in the lung reduces the fibrotic response to bleomycin.

Pulmonary fibrosis is a chronic progressive disease with no effective therapy. Transforming growth factor beta (TGF-beta) is thought to be a key profibrotic mediator and blocking its activity is therefore one of the targets of new treatment strategies for fibrosis. Decorin is an endogenous proteoglycan and one of the known inhibitors of TGF-beta. The short half-life of peptide-based therapeutics makes gene transfer a promising approach to achieve prolonged protein levels in the lung. Replication-deficient adenovirus was used to deliver decorin transgene (AdDec) to the airways by a single intranasal injection in a murine bleomycin model of lung fibrosis. The ability of vector-derived decorin to inhibit TGF-beta was examined in a bioassay and its effect on bleomycin-induced pulmonary fibrosis was determined by histomorphology and lung hydroxyproline. In vitro, supernatant from cells infected with AdDec abrogated the bioactivity of TGF-beta in a dose-dependent manner whereas control virus (AdDL70) had no effect. In vivo, treatment of bleomycin-injected mice with AdDec substantially reduced the fibrogenic response compared with control virus (hydroxyproline: bleomycin/AdDec, 1.96 microg/mg; bleomycin/AdDL70, 3.05 microg/mg; p = 0.0005). These results suggest that a single administration of AdDec was able to generate a local pulmonary environment that effectively blocked the fibrogenic response to bleomycin by inhibition of TGF-beta.

Adenoviridae↗
PubMed1988

The intensity of chronic lung inflammation and fibrosis after bleomycin is directly related to the severity of acute injury.

Interstitial lung disease is thought to result from progression of an initial lung injury and alveolitis into a chronic inflammatory process that produces fibrosis. However, the relationship between the severity of the initial phase of acute injury and alveolitis and the amount of subsequent chronic inflammation and fibrosis remains unclear. We induced a wide spectrum of acute lung injury in rabbits by using various amounts of intratracheal bleomycin (5 or 10 U/kg) with and without oxygen supplementation (100% O2 for 2 min). The arterial oxygen tension on Day 12 after the bleomycin correlated with the extent of acute lung injury, as well as with the amount of chronic inflammation and fibrosis present on Day 56, as determined by physiologic parameters (lung volume, DLCO/VA, and PO2), and morphometry (volume proportions abnormal parenchyma made up of intra-alveolar macrophages, intra-alveolar granulocytes, abnormal alveoli, abnormal airways, fibrosis, consolidation, and honeycombing). We conclude that in bleomycin-induced interstitial lung disease in the rabbit, there is a direct relationship between the severity of acute lung injury after intratracheal bleomycin and the amount of subsequent chronic inflammation and fibrosis. This suggests that the mechanisms regulating the development of fibrosis are directly influenced by the extent of initial injury.

Acute Disease↗
PubMed1989

Accumulation of hyaluronic acid in the alveolar interstitial tissue in bleomycin-induced alveolitis.

By using biotin-labeled proteoglycan core protein and an avidin-enzyme system, hyaluronic acid (HA) was visualized in the lungs of rats at different times (4, 10, and 20 days) after bleomycin injury. Four days after an intratracheal injection of bleomycin, HA was accumulated in the edematous alveolar septa of the focal areas with lung tissue injury. An interstitial cellular infiltrate of mainly lymphocytes was present. In normal rat lung, HA was not seen in the alveolar tissue but confined to peribronchial and perivascular spaces. Ten and twenty days after bleomycin administration, increasing numbers of macrophages were apparent in the alveolar space. Proliferating fibroblasts and deposition of collagen in the alveolar tissue were observed while the diffuse HA accumulation was becoming less prominent in the alveolar interstitial tissue. HA was more distinctly located in the surroundings of proliferating fibroblasts. A few scattered alveolar macrophages showed a positive staining for HA. An increased water content of the lung was most apparent 4 days after bleomycin administration. The accumulation of HA, a glycosaminoglycan with unique qualities to immobilize water, in the alveolar interstitium suggests a role for HA in the alveolar interstitial edema. The appearance of HA in alveolar macrophages might indicate that macrophage phagocytosis contributes to the elimination of HA from inflamed lung tissue.

Animals↗
PubMed1989

Hyaluronan (hyaluronic acid) in bronchoalveolar lavage fluid during the development of bleomycin-induced alveolitis in the rat.

Hyaluronan (hyaluronate or hyaluronic acid) was measured in bronchoalveolar lavage (BAL) fluid from rats during a 30-day period after a single intratracheal dose of bleomycin. An increase of hyaluronan (HA) in BAL fluid was apparent by 3 days after bleomycin administration. Peak HA values were reached on Day 5 and were about 75 times higher than in control animals. Analyses of urea in BAL and HA in serum indicated that the increased levels of HA in BAL, postbleomycin, could not be explained by plasma leakage. The HA recovered by lavage decreased progressively after Day 5 and returned to normal 3 wk after bleomycin treatment. The HA content and an increased influx of PMN in BAL fluid were correlated and showed a similar time dependence, suggesting that enhanced synthesis of HA in the smaller airways is linked to the early inflammatory phase of the bleomycin injury.

Animals↗
PubMed1991

Early changes in lung tissue hyaluronan (hyaluronic acid) and hyaluronidase in bleomycin-induced alveolitis in hamsters.

Intratracheal instillation of bleomycin in hamsters initiates a series of events that mimic human interstitial pulmonary fibrosis. Because glycosaminoglycans and particularly hyaluronan (hyaluronic acid, HA), may play an important role in the extracellular matrix response to early injury and subsequent fibrosis, this study was undertaken to define the early time course of changes in HA and hyaluronidase. Hamsters were given either 1 unit bleomycin sulfate in 0.2 ml saline or 0.2 ml saline (control), and randomly selected animals from both groups were killed at Days 3, 5, 6, 7, 9, and 17. Glycosaminoglycan fractions prepared from lung tissue of individual animals were analyzed for HA. The maximal HA content was reached 6 days after instillation of bleomycin and was 14.6-fold the normal value. The weight of injured lungs was 2.3-fold the control value. Thus, the increase in HA content was 30-fold. By Day 7 the HA content had dropped sharply. It then declined gradually to approximately double control values at Day 17. The specific activity of lysosomal hyaluronidase was the same in bleomycin-treated lungs and control lungs. Total units of the enzyme were increased in injured lungs, even at the time of maximal HA content, indicating active turnover of HA. The maximal HA content occurs prior to the rise in collagen and elastin biosynthesis. This observation in addition to the magnitude of the increase and its abrupt decline suggest that HA may be an important initiating factor for pathologic changes in lung extracellular matrix components.

Animals↗
PubMed1983

Bleomycin-induced changes in the carbon monoxide transfer factor of the lungs and its components.

To study subclinical pulmonary toxicity of bleomycin we measured the single-breath carbon monoxide transfer factor (TLCO) and its components, pulmonary capillary blood volume (Vc), diffusing capacity of the alveolar-capillary membrane (Dm), and vital capacity (VC) in a homogenous group of 18 patients with testicular nonseminomatous germ cell tumor treated with bleomycin, vinblastine, and cis-diammine-dichloroplatinum (DDP). The most prominent finding was a substantial decrease in Vc (p less than 0.001) with only minor, though significant, changes in the other parameters. No recovery of pulmonary function had taken place 4 months after the last dose of bleomycin. The importance of correcting TLCO for hemoglobin concentration is shown. We conclude that vascular damage may be an important feature of subclinical pulmonary injury caused by bleomycin given in combination with vinblastine and DDP. In the postbleomycin phase, other forms of potentially lung-toxic treatment should be instituted with care.

Adult↗
PubMed1984

Characteristics of cultured lung fibroblasts from bleomycin-treated rats. Comparisons with in vitro exposed normal fibroblasts.

Bleomycin is an antineoplastic agent that causes pulmonary fibrosis. This report describes fibroblasts cultured from lung tissue explants of in vivo bleomycin-exposed and control rats. Proliferation of cultured fibroblasts from bleomycin-exposed lungs was decreased compared with that from control cultures, both in rate of growth and maximal cell yield. The diminished proliferative capacity of these fibroblasts from exposed lungs persisted over 9 wk of serial subcultivation. Fibroblast cultures from exposed lungs typically had a greater proportion of large cells exhibiting extensive cytoskeletal structures than did control cultures. Comparisons of these fibroblasts with normal fibroblasts exposed in vitro to bleomycin showed similarities in size, morphologic features, and proliferation.

Animals↗
PubMed1985

Structure-function correlation of early stages of lung injury induced by intratracheal bleomycin in the rabbit.

After measurement of lung volume, pressure-volume relationship of the lungs, flow-volume relationship, and single-breath diffusing capacity, the effect of endotracheal injection of bleomycin (10 micrograms/kg) on structural and functional changes was assessed in 21 rabbits and compared with 8 rabbits who received endotracheal injection of saline. Lung function was reassessed in the control rabbits at 1, 3, and 5 wk, and they were then killed. The bleomycin-treated rabbits were divided into 3 groups and retested at 1 (n = 7), 3 (n = 6), and 5 (n = 8) wk. Each group of animals was killed after the functional assessment, and after fixation the lungs were examined morphometrically. The degree of fibrosis in the bleomycin-treated animals was small even at 5 wk. Volume densities of pulmonary structures, alveolar wall thickness, airway diameters, airway inflammation scores, and fibrosis scores were determined and their correlation with the functional measurements was assessed. Lung volume subdivisions, pressure-volume characteristics, and diffusing capacity for carbon monoxide were significantly reduced, and the resistance of the upstream segment of airways was significantly increased after the bleomycin injection. Changes in lung volume correlated significantly with the volume densities of free alveolar cells, nonparenchymal tissue, and alveolar wall thickness. The exponent K, derived by fitting an exponential function to the pressure-volume data, which is indicative of lung elastic behavior, did not correlate with any morphometric index of interstitial disease. The diffusing capacity for CO was significantly correlated with the volume densities of alveolar wall, nonparenchymal tissue, and alveolar wall thickness, but these correlations became nonsignificant when the diffusing capacity was corrected for alveolar volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2004

CXCL11 attenuates bleomycin-induced pulmonary fibrosis via inhibition of vascular remodeling.

Aberrant vascular remodeling is a central hallmark for the development and progression of idiopathic pulmonary fibrosis. The mechanisms underlying the pathophysiologic alterations, however, are poorly understood. A recent phase II trial of interferon gamma-1b has demonstrated a trend toward a decrease in profibrotic and proangiogenic biologic markers, and upregulation of lung CXCL11 mRNA and bronchoalveolar lavage fluid and plasma protein levels of CXCL11. We hypothesized that net aberrant vascular remodeling seen during the pathogenesis of fibroplasia and deposition of extracellular matrix during bleomycin-induced pulmonary fibrosis can be attenuated by treatment with the angiostatic ELR(-) CXC chemokine, CXCL11. In a preclinical model, systemic administration of CXCL11 reduced pulmonary collagen deposition, procollagen gene expression, and histopathologic fibroplasia and extracellular matrix deposition in the lung of bleomycin-treated mice. CXCL11 treatment significantly reduced bleomycin-induced pulmonary fibrosis without altering specific lung leukocyte populations. CXCR3 is not expressed on fibroblasts and CXCL11 had no direct functional effect on pulmonary fibroblasts. The angiogenic activity in the lung was significantly decreased, however, and CXCL11 treatment reduced the total number of endothelial cells in the lung following bleomycin exposure. The results suggest that CXCL11 inhibits pulmonary fibrosis by altering aberrant vascular remodeling.

Angiogenesis Inhibitors↗
PubMed2006

A novel IkappaB kinase-beta inhibitor ameliorates bleomycin-induced pulmonary fibrosis in mice.

RATIONALE: IkappaB kinase-beta is a critical regulator in the activation of nuclear factor-kappaB (NF-kappaB), a transcription factor related to the expression and regulation of proinflammatory cytokines. OBJECTIVE: To evaluate if inhibition of IkappaB kinase-beta ameliorates pneumonitis and pulmonary fibrosis. METHODS: We examined whether a novel IkappaB kinase-beta inhibitor, IMD-0354, attenuates bleomycin-induced pulmonary fibrosis in mice. MEASUREMENTS AND MAIN RESULTS: Administration of IMD-0354 significantly improved the loss of body weight and survival of mice treated with bleomycin, whereas IMD-0354 alone did not cause any morphologic change in the lung. When mice were evaluated 28 d after bleomycin administration, IMD-0354 dose-dependently reduced the collagen content and fibrotic scores as shown by histologic examination. The findings in the bronchoalveolar lavage demonstrated that the proportions of neutrophils and lymphocytes were decreased in mice treated with IMD-0354 on Day 7 and 14, respectively. IMD-0354 treatment was confirmed to inhibit the activation of NF-kappaB, but not activator protein-1, in the lungs treated with bleomycin. The production of inflammatory cytokines tumor necrosis factor-alpha and interleukin-1beta was reduced in the lungs of mice treated with IMD-0354. CONCLUSIONS: These results suggest that IMD-0354 might be useful to ameliorate the inflammation in the lungs induced by fibrotic injury and the subsequent fibrogenesis via inhibiting the expression of profibrotic cytokines related to the activation of NF-kappaB.

Animals↗
PubMed2006

Gefitinib prevents bleomycin-induced lung fibrosis in mice.

RATIONALE: Transforming growth factor-alpha and epidermal growth factor (EGF), the ligands for EGF receptor (EGFR), stimulate fibroblast proliferation and play an important role in the pathogenesis of pulmonary fibrosis. Therefore, inhibition of the EGFR signal by an EGFR tyrosine kinase inhibitor (EGFR-TKI) may prevent pulmonary fibrosis. However, there is a possibility that blocking the EGFR signal may inhibit epithelial cell repair, thereby exaggerating lung fibrosis. OBJECTIVE: To investigate the effect of EGFR-TK inhibition on lung fibrosis. METHODS: We looked at the effects of the EGFR-TKIs gefitinib (20, 90, 200 mg/kg) and AG1478 (12 mg/kg) on a bleomycin-induced lung fibrosis model in mice. MEASUREMENTS AND MAIN RESULTS: Gefitinib prevented lung fibrosis at all three doses. Furthermore, in those mice that did not receive bleomycin treatment, gefitinib at 200 mg/kg did not induce lung fibrosis. Immunohistochemistry revealed that phosphorylation of EGFR in lung mesenchymal cells induced by bleomycin was inhibited by gefitinib. AG1478 also attenuated the lung fibrosis. In vitro studies further demonstrated that the addition of gefitinib or AG1478 suppressed the EGFR ligand-induced proliferation of lung fibroblasts. CONCLUSIONS: These findings suggest that, in the preclinical setting, EGFR-TKIs may have a protective effect on lung fibrosis induced by bleomycin. Because these molecular targeted drugs may have differing effects depending on species and individuals, a cautious interpretation is warranted.

Animals↗
PubMed1996

Plasmin regulates the activation of cell-associated latent TGF-beta 1 secreted by rat alveolar macrophages after in vivo bleomycin injury.

Transforming growth factor beta s (TGF-beta s) are 25-kD multifunctional proteins that regulate inflammation and connective tissue synthesis. With rare exception TGF-beta 1 is secreted noncovalently bound to a latency-associated peptide (LAP) that renders the mature TGF-beta 1 biologically inactive. An important mechanism for the control of TGF-beta 1 action is the regulation of the post-translational processing that removes the LAP from the mature peptide and renders it biologically active. In a model of pulmonary inflammation and fibrosis induced by the antineoplastic antibiotic, bleomycin, we have demonstrated that explanted alveolar macrophages secrete progressively increasing quantities of a biologically active form of TGF-beta 1, the secretion of which was maximal 7 days after bleomycin administration. Thereafter, there was a rapid decline in the secretion of the active form of TGF-beta 1, whereas the latent form continued to be secreted in elevated quantities. Plasmin, a serine protease, was transiently generated by the same bleomycin-activated alveolar macrophages and paralleled the rise in active TGF-beta 1. When alpha 2-antiplasmin, an inhibitor of plasmin, was added to cultures of alveolar macrophages, the post-translational activation of L-TGF-beta 1, was totally abrogated. When plasmin was added to alveolar macrophages in culture, there was complete activation of the L-TGF-beta 1 that had been secreted during the culture period. However, there was no effect of plasmin on the same alveolar macrophage-derived L-TGF-beta 1 in cell-free conditioned media. Our findings suggest that the secretion of an active form of TGF-beta 1 by alveolar macrophages is regulated by the generation of plasmin and requires that the alveolar macrophages be present. Because the diminution of active TGF-beta 1 coincides with the resolution of inflammation, this suggests that the availability of plasmin regulates the biologically active form of TGF-beta 1, and thus, the inflammation seen after bleomycin-induced lung injury.

Animals↗
PubMed1998

Increased endothelin-1 and its localization during the development of bleomycin-induced pulmonary fibrosis in rats.

Endothelin-1 (Et-1) has been implicated in the pathogenesis of pulmonary fibrosis with increased levels in the lung tissue of patients with pulmonary fibrosis and profibrotic effects in vitro. In this study we have investigated the temporal changes in lung Et-1 levels and immunohistochemical localization in relation to collagen deposition during the development of bleomycin-induced pulmonary fibrosis in rats. Lung Et-1 content doubled by 3 d following the intratracheal instillation of bleomycin, and continued to increase up to 7 d when values were about threefold greater than controls. Thereafter, the values for bleomycin-treated animals remained constant up to 21 d. There was no change in collagen content at 3 d but after 7 d there was a 25% increase and by 21 d levels were almost double those of the controls. In normal lung, Et-1 was predominantly associated with epithelial cells of conducting and nonconducting airways. Following bleomycin administration, intense staining of macrophages and conducting airway and alveolar epithelial cells was observed with marked staining of perivascular, peribronchiolar, and alveolar septal connective tissue, as well as the venular and arterial intima and media. These results demonstrate elevation of Et-1 levels prior to an increase in collagen content which, along with its localization within developing fibrotic lesions, provides further evidence of a profibrotic role for Et-1 in the pathogenesis of pulmonary fibrosis.

Animals↗
PubMed2000

Induction of telomerase activity in fibroblasts from bleomycin-injured lungs.

Bleomycin-induced lung injury causes increased fibroblast numbers in the lung and pulmonary fibrosis. Studies of fibroblasts isolated from such injured lungs have revealed evidence of increased intrinsic proliferative capacity, but the mechanism is unknown. Telomerase catalyzes the addition of telomeric DNA repeats onto chromosomal ends, which is associated with increased cellular life span or immortality. To examine whether telomerase might play a role in regulating fibroblast proliferative capacity in pulmonary fibrosis, lung fibroblasts were isolated from rats treated with endotracheal injections of phosphate-buffered saline or bleomycin. At selected time points, the rats were killed and lung fibroblasts isolated. The isolated cells and lung tissue were then used in experiments for measurement of telomerase activity. The results show undetectable telomerase activity in fibroblasts isolated from control uninjured lungs, or in the control lung tissue extracts. Similar results were obtained in cells and lung tissue from Days 1, 3, and 28 bleomycin-injured lungs. However, significant telomerase activity was detected in fibroblasts and tissue extracts isolated from Days 7, 14, and 21 bleomycin-treated rat lungs, with maximal activity observed in the Day 14 samples. Analysis of the isolated cells for telomerase messenger RNA or reverse transcriptase expression, combined with alpha-smooth-muscle actin expression by immunohistochemistry, revealed that telomerase expression localized primarily to nonmyofibroblasts. These findings suggest that in addition to elevated growth factor expression, the injured lung fibroblast population may contain cells with increased life span, which could contribute to the observed overall increase in lung fibroblast numbers.

Animals↗
PubMed2003

Overexpression of tumor necrosis factor-alpha diminishes pulmonary fibrosis induced by bleomycin or transforming growth factor-beta.

Tumor necrosis factor-alpha (TNF-alpha) is thought to be important in the development of pulmonary fibrosis. However, surfactant protein-C/TNF-alpha transgenic mice do not spontaneously develop pulmonary fibrosis but instead develop alveolar enlargement and loss of elastic recoil. We hypothesized that overexpression of TNF-alpha in the lung requires an additional insult to produce fibrosis. In this study we evaluated whether TNF-alpha overexpression altered the development of pulmonary fibrosis due to bleomycin or transforming growth factor-beta (TGF-beta). Either 0.2 U bleomycin or saline was administered into left lung of TNF-alpha transgenic mice and their transgene-negative littermates. To overexpress TGF-beta, an adenovirus vector containing either active TGF-beta (AdTGF-beta) or LacZ was administered at a dose of 3 x 108 plaque-forming units per mouse. Fibrosis was assessed histologically and by measurement of hydroxyproline. TNF-alpha transgenic mice tolerated bleomycin or AdTGF-beta, whereas the transgene-negative littermates demonstrated severe pulmonary fibrosis after either agent. An increase in prostaglandin E2 and downregulation of TNF receptor I expression were observed in the TNF-alpha transgenic mice. In addition, recombinant human TNF-alpha attenuated bleomycin-induced pulmonary fibrosis. TNF-alpha has a complex role in the development of pulmonary fibrosis. Endogenous TNF-alpha may be important in the development of fibrosis as indicated in other reports, but overexpression of TNF-alpha or exogenous TNF-alpha limits pulmonary fibrosis in mice.

Adenoviridae↗
PubMed1985

Rat lung fibroblast collagen metabolism in bleomycin-induced pulmonary fibrosis.

Endotracheal bleomycin administration in rats and other animal species causes rapid development of pulmonary fibrosis, characterized by increased lung collagen synthesis and deposition. To clarify the mechanism, lung fibroblasts from bleomycin-treated rats (BRF) were isolated and maintained in tissue culture. They were then compared with those from normal untreated control animals, with respect to several key parameters of collagen metabolism. BRF synthesized collagen at a rate 35-82% above normal rat lung fibroblasts (NRF). This difference did not appear to be due to the selection of a clone by the subculture process. Furthermore, analysis of newly synthesized collagen type composition, revealed a significantly lower ratio of type III to type I collagen. Noncollagenous protein synthesis, however, was not significantly different from normal. Collagenase production and growth rate were also unaffected. BRF, however, was morphologically indistinguishable from NRF, even at the ultrastructural level. Upon further bleomycin (1 microgram/ml) exposure in vitro, BRF could be further stimulated to synthesize collagen at 82% above the rate for untreated BRF. This is comparable to the 90% increase in NRF treated in vitro (compared with untreated NRF). These results would favor the conclusion that bleomycin induces pulmonary fibrosis, by causing directly and/or indirectly lung fibroblasts (or a certain line of lung fibroblasts) to synthesize collagen at a higher rate without any associated increase in growth rate. The data, however, do not rule out the possibility that the fibroblast isolation procedure has selected for a certain population of fibroblasts that may not be typical of the in vivo situation.

Animals↗
PubMed1986

Augmentation of fibroblast proliferation by bleomycin.

Bleomycin-induced lung disease is characterized by fibroblast proliferation and pulmonary fibrosis. In these studies, we demonstrate that fibroblasts are relatively resistant to clinically relevant amounts (below 10(-4) U/ml) of bleomycin and that these levels of bleomycin augment fibroblast proliferation in response to various fibroblast growth factors. These observations suggest that one mechanism by which bleomycin causes pulmonary fibrosis is augmentation of fibroblast proliferation.

Bleomycin↗