Association between occupational dust exposure and prognosis of idiopathic pulmonary fibrosis: a Korean national survey.

BACKGROUND: Previous studies have investigated the relationship between occupational and environmental agents and idiopathic pulmonary fibrosis (IPF). However, there have been few studies regarding the prognosis of patients with IPF according to patient occupation. METHODS: We investigated whether occupational dust exposure was associated with clinically decreased lung function and poor prognosis. The Korean Interstitial Lung Disease Research Group conducted a national survey to evaluate the clinical, physiologic, radiologic, and survival characteristics of patients with IPF. A total of 1,311 patients with IPF were stratified into five groups according to their occupation: (1) unemployed or homemakers (n = 628); (2) farmers, fishers, or ranchers (n = 230); (3) sales or service personnel (n = 131); (4) clerical or professional personnel (n = 151); and (5) specific dust-exposed workers (n = 171). RESULTS: The mean age of subjects at diagnosis, was 67.5 ± 9.7 years. Current smokers were 336 patients, 435 were exsmokers, and 456 were never smokers. Dust-exposed workers showed early onset of IPF (61.3 ± 8.6 years; P < .001) and a longer duration of symptoms at diagnosis (17.0 ± 28.2 months; P = .004). Aging (P = .001; hazard ratio [HR], 1.034; 95% CI, 1.014-1.054), FVC % predicted at diagnosis (P = .004; HR, 0.984; 95% CI, 0.974-0.995), and dust-exposure occupation (P = .033; HR, 1.813; 95% CI, 1.049-3.133) were associated with mortality. CONCLUSIONS: These findings indicate that occupational dust may be an aggravating factor associated with a poor prognosis in IPF.

Idiopathic pleuroparenchymal fibroelastosis presenting in recurrent pneumothorax: a case report.

Idiopathic pleuroparenchymal fibroelastosis (PPFE) is a rare, recently classified entity that consists of pleural and subjacent parenchymal fibrosis predominantly in the upper lungs. In an official American Thoracic Society/European Respiratory Society statement in 2013, this disease is introduced as a group of rare idiopathic interstitial pneumonias. We describe a case of a 76-year-old woman with cough and recurrent pneumothorax. She was admitted to our hospital with severe cough at first. High resolution computed tomography (HRCT) disclosed multifocal subpleural consolidations with reticular opacities in both lungs, primarily in the upper lobes, suggesting interstitial pneumonia. Rheumatoid lung was diagnosed initially through an elevated rheumatoid factor, HRCT and surgical biopsy at the right lower lobe. However, one month later, pneumothorax recurred. Surgical biopsy was performed at the right upper lobe at this time. The specimens revealed typical subpleural fibroelastosis. We report this as a first case of idiopathic PPFE in Korea after reviewing the symptoms, imaging and pathologic findings.

Thrombin induces epithelial-mesenchymal transition via PAR-1, PKC, and ERK1/2 pathways in A549 cells.

Thrombin activates protease-activated receptor (PAR)-1 and induces a myofibroblast phenotype in normal lung fibroblasts. The origins of myofibroblasts are resident fibroblasts, fibrocytes, and epithelial-mesenchymal transition (EMT). We investigated the effects of thrombin, an important mediator of interstitial lung fibrosis, on EMT in A549 human alveolar epithelial cells. We show that thrombin induced EMT and collagen I secretion through the activation of PAR-1, and PKC and ERK1/2 phosphorylation in A549 cells. These effects were largely prevented by a specific PAR-1 antagonist, short interfering RNA (siRNA) directed against PAR-1, or specific PKCα/ß, δ, and ε inhibitors. These data indicated that interaction with thrombin and alveolar epithelial cells might directly contribute to the pathogenesis of pulmonary fibrosis through EMT. Targeting PAR-1 on the pulmonary epithelium or specific inhibitors to PKCα/ß, δ, and ε might stop the fibrotic processes in human idiopathic pulmonary fibrosis by preventing thrombin-induced EMT.

A multicenter phase II study of belotecan, a new camptothecin analogue, in elderly patients with previously untreated, extensive-stage small cell lung cancer.

PURPOSE: Belotecan is a new camptothecin analogue and a potent topoisomerase I inhibitor. The aim of this phase II study was to investigate the efficacy and toxicity of belotecan in previously untreated elderly patients with small cell lung cancer (SCLC). METHODS: A total of 26 patients, aged ≥65 years, with previously untreated, extensive-stage SCLC were enrolled in the study. Belotecan was administered by daily intravenous infusion at 0.5 mg/m(2)/day for 5 consecutive days every 3 weeks. RESULTS: The overall response rate and disease control rate of chemotherapy on an intention-to-treat basis were 35 and 54 %, respectively. The median overall survival was 6.4 months, and the median time to progression was 2.8 months. The most common toxicity was hematologic. Grade 3 or 4 neutropenia occurred in 80.8 % of patients, and grade 3 or 4 thrombocytopenia in 15.3 %. Non-hematologic toxic effects of grade 3 or 4 were uncommon. CONCLUSION: Belotecan had modest efficacy and well-tolerated toxicity in previously untreated, elderly SCLC patients. Single belotecan could be a promising treatment option, considering its lower toxicity in elderly patients who are unsuitable candidates for platinum plus etoposide chemotherapy.

Inhibitory effect of receptor for advanced glycation end products (RAGE) on the TGF-ß-induced alveolar epithelial to mesenchymal transition.

Idiopathic pulmonary fibrosis (IPF) is a lethal parenchymal lung disease characterized by myofibroblast proliferation. Alveolar epithelial cells (AECs) are thought to produce myofibroblasts through the epithelial to mesenchymal transition (EMT). Receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily of cell surface receptors whose activation is associated with renal fibrosis during diabetes and liver fibrosis. RAGE is expressed at low basal levels in most adult tissues except the lung. In this study, we evaluated the interaction of ligand advanced glycation end products (AGE) with RAGE during the epithelial to myofibroblast transition in rat AECs. Our results indicate that AGE inhibited the TGF-ß-dependent alveolar EMT by increasing Smad7 expression, and that the effect was abolished by RAGE siRNA treatment. Thus, the induction of Smad7 by the AGE-RAGE interaction limits the development of pulmonary fibrosis by inhibiting TGF-ß-dependent signaling in AECs.

A multicenter phase II study of belotecan, a new camptothecin analogue, as a second-line therapy in patients with small cell lung cancer.

Belotecan (Camtobell, CKD602) is a new camptothecin derivative antitumor agent that belongs to the topoisomerase inhibitors. The aim of this phase II study was to evaluate the efficacy and safety of single agent belotecan as a second-line therapy in patients with small cell lung cancer (SCLC). Patients who were previously treated for SCLC were entered into the study. Belotecan was given by daily intravenous infusion for five consecutive days, every three weeks. Twenty-five patients were enrolled in this study. On an intention-to-treat basis, belotecan induced an overall response rate of 24%, a median overall survival of 9.9 months, a median time to progression of 2.2 months, and a 1-year survival rate of 38.3%. Grade 3/4 neutropenia developed in 88.0% of patients and grade 3/4 thrombocytopenia in 40.0%. Nonhematologic toxicity of grade 3 or 4 was low. The results suggest that belotecan is relatively active and well tolerated as a second-line agent in patients with SCLC.

Inhibitory effect of CXC chemokine receptor 4 antagonist AMD3100 on bleomycin induced murine pulmonary fibrosis.

CXC chemokine receptor 4 (CXCR4), which binds the stromal cell-derived factor-1 (SDF-1), has been shown to play a critical role in mobilizing the bone marrow (BM)-derived stem cells and inflammatory cells. We studied the effects of AMD3100, CXCR4 antagonist, on a murine bleomycin-induced pulmonary fibrosis model. Treatment of mice with AMD3100 in bleomycin-treated mice resulted in the decrease of SDF-1 in bronchoalveolar lavage (BAL) fluids at an early stage and was followed by the decrease of fibrocytes in the lung. AMD3100 treatment decreased the SDF-1 mRNA expression, fibrocyte numbers in the lung at an early stage (day 3) and CXCR4 expression at the later stage (day 7 and 21) after bleomycin injury. The collagen content and pulmonary fibrosis were significantly attenuated by AMD3100 treatment in later stage of bleomycin injury. AMD3100 treatment also decreased the murine mesenchymal and hematopoietic stem cell chemotaxis when either in the stimulation with bleomycin treated lung lysates or SDF-1 in vitro. In BM stem cell experiments, the phosphorylation of p38 MAPK which was induced by SDF-1 was significantly blocked by addition of AMD3100. Our data suggest that AMD3100 might be effective in preventing the pulmonary fibrosis by inhibiting the fibrocyte mobilization to the injured lung via blocking the SDF-1/CXCR4 axis.

Effects of elastase inhibitor on the epithelial cell apoptosis in bleomycin-induced pulmonary fibrosis.

Alveolar epithelial cell injury and apoptosis is consistent findings in human idiopathic pulmonary fibrosis (IPF). Epithelial cell apoptosis is known to be induced by leukocyte elastase in vitro. The authors hypothesized that synthetic neutrophil elastase inhibitor, sivelestat (ONO-5046), can inhibit the bleomycin-induced pulmonary fibrosis in rats by blocking the apoptotic pathways in epithelial cells. Adult rats were injected with intratracheal bleomycin. Sivelestat was given for 13 days intraperitoneally after bleomycin treatments. Similar experiments were carried out in which A549 cells, a human alveolar type II epithelial cell line, were treated with bleomycin or neutrophil elastase. In rats, sivelestat decreased neutrophil counts and the cytokine-induced neutrophil chemoattractant (CINC)-1 in the bronchoalveolar lavage (BAL) fluid of bleomycin-treated rats. Sivelestat also decreased the bleomycin-induced lung inflammatory cell apoptosis by decreasing caspase-3 and -9 activities. In A549 cells, sivelestat decreased the elastase-induced epithelial cell apoptosis but not the bleomycin-induced epithelial cell apoptosis. Similarly, sivelestat inhibited the elastase-induced cell death but not the bleomycin-induced cell death in MTT assays. Sivelestat also inhibited the elastase-induced caspase-3 and -9 activities and cytochrome c release from the mitochondria but did not inhibit the bleomycin-induced caspase activities in A549 cells. In conclusion, bleomycin caused the lung inflammatory cell apoptosis through the caspase-9 and -3 pathways in rats. Sivelestat inhibited pulmonary fibrosis by blocking these mitochondria-mediated apoptotic pathways in bleomycin-treated rats and in elastase-treated A549 cells. These findings suggest that sivelestat can suppress the bleomycin-induced pulmonary fibrosis by blocking neutrophil chemotaxis and by inhibiting the neutrophil elastase-induced lung cell apoptosis in rats.

Risk factors for acute respiratory distress syndrome during neutropenia recovery in patients with hematologic malignancies.

INTRODUCTION: Neutropenia recovery may be associated with deterioration in oxygenation and exacerbation of pre-existing pulmonary disease. However, risk factors for acute respiratory distress syndrome (ARDS) during neutropenia recovery in patients with hematologic malignancies have not been studied. METHODS: We studied critically ill patients with hematologic malignancies with the dual objectives of describing patients with ARDS during neutropenia recovery and identifying risk factors for ARDS during neutropenia recovery. A cohort of consecutive neutropenic patients with hematologic malignancies who were admitted to the intensive care unit (ICU) was studied. During a 6-year period, 71 patients recovered from neutropenia, of whom 38 (53.5%) developed ARDS during recovery. RESULTS: Compared with non-ARDS patients, patients who experienced ARDS during neutropenia recovery were more likely to have pneumonia, be admitted to the ICU for respiratory failure, and receive mechanical ventilator therapy. The in-ICU mortality was significantly different between the two groups (86.8% versus 51.5%, respectively, for patients who developed ARDS during neutropenia recovery versus those who did not during neutropenia recovery). In multivariate analysis, only occurrence of pneumonia during the neutropenic episode was associated with a marked increase in the risk of ARDS (odds ratio, 4.76). CONCLUSIONS: Patients with hematologic malignancies complicated by pneumonia during neutropenia are at increased risk for ARDS during neutropenia recovery.

The soluble tumor necrosis factor-alpha receptor suppresses airway inflammation in a murine model of acute asthma.

PURPOSE: Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine that has been implicated in many aspects of the airway pathology in asthma. TNF-alpha blocking strategies are now being tried in asthma patients. This study investigated whether TNF-alpha blocking therapy inhibits airway inflammation and airway hyperresponsiveness (AHR) in a mouse model of asthma. We also evaluated the effect of TNF-alpha blocking therapy on cytokine production and adhesion molecule expression. MATERIALS AND METHODS: Ovalbumin (OVA) sensitized BALB/c female mice were exposed to intranasal OVA administration on days 31, 33, 35, and 37. Mice were treated intraperitoneally with soluble TNF-alpha receptor (sTNFR) during the OVA challenge. RESULTS: There were statistically significant decreases in the numbers of total cell and eosinophil in bronchoalveolar lavage fluid (BALF) in the sTNFR treated group compared with the OVA group. However, sTNFR-treatment did not significantly decrease AHR. Anti-inflammatory effect of sTNFR was accompanied with reduction of T helper 2 cytokine levels including interleukin (IL)-4, IL-5 and IL-13 in BALF and vascular cell adhesion molecule 1 expression in lung tissue. CONCLUSION: These results suggest that sTNFR treatment can suppress the airway inflammation via regulation of Th2 cytokine production and adhesion molecule expression in bronchial asthma.

Nitric oxide induces MUC5AC mucin in respiratory epithelial cells through PKC and ERK dependent pathways.

BACKGROUND: Nitric oxide (NO) is generally increased during inflammatory airway diseases. This increased NO stimulates the secretion of mucin from the goblet cell and submucosal glands but the mechanism is still unknown precisely. In this study, we investigated potential signaling pathways involving protein kinase C (PKC) and mitogen-activated protein kinase (MAPK) in the NO-induced MUC5AC mucin gene and protein expression in A549 cells. METHODS: Nitric oxide was donated to the A549 cells by NOR-1. MUC5AC mucin levels were assayed by enzyme-linked immunosorbent assay (ELISA). MUC5AC promoter activity was determined by measuring luciferase activity after the lysing the transfected cells. Activation of PKC isoforms were measured by assessing the distribution of the enzyme between cytosolic and membrane fractions using immunoblotting. Immunoblotting experiments using a monoclonal antibody specific to PKC isoforms were performed in the cytosol and membrane fractions from A549 cells. Western blot analysis for pERK and p38 were performed using the corresponding antibodies from the cell lysates after donating NO to the A549 cells by NOR-1. RESULTS: The transcriptional activity of MUC5AC promoter was maximal at the concentration of 0.1 mM NOR-1 for 1 hour incubation in transfected A549 cells. (+/-)-(E)-methyl-2-((E)-hydroxyimino)-5-nitro-6-methoxy-3-hexenamide (NOR-1) markedly displaced the protein kinase C (PKC)alpha and PKCdelta from the cytosol to the membrane. Furthermore, the PKC-alpha,betainhibitors, GO6976 (10 nM) and PKCdelta inhibitors, rottlerin (4 muM) inhibited the NOR-1 induced migration of PKCalpha and PKCdelta respectively. NOR-1 also markedly increased the MUC5AC promoter activity and mRNA expression, mucin synthesis and ERK1/2 phosphorylation. The PKC inhibitors also inhibited the NOR-1 induced MUC5AC mRNA and MUC5AC protein synthesis by inhibiting the activation of PKCalpha and PKCdelta with ERK1/2 pathways. CONCLUSION: Exogenous NO induced the MUC5AC mucin gene and protein through the PKCalpha and PKCdelta-ERK pathways in A549 cells. Inhibition of PKC attenuated NO-mediated MUC5AC mucin synthesis. In view of this findings, PKC inhibitors might be useful in the treatment of bronchial asthma and chronic bronchitis patients where NO and mucus are increased in the bronchial airways.

A case of chronic myelomonocytic leukemia with severe eosinophilia having t(5;12)(q31;p13) with t(1;7)(q10;p10).

We describe an unusual case of chronic myelomonocytic leukemia with severe eosinophilia having t(5;12)(q31;p13) with t(1;7)(q10;p10). The eosinophilic proliferation was severe in peripheral blood and bone marrow, and they revealed marked dysplastic features. We performed fluorescence in situ hybridization (FISH) and immunohistochemistry to evaluate the clonality of eosinophils. The eosinophils were stained positively to platelet-derived growth factor receptor-beta. By FISH using chromosome 1 satellite probe and chromosome 1q telomere probe, the eosinophils were proved to belong to the malignant clone.

Neutrophil elastase causes MUC5AC mucin synthesis via EGF receptor, ERK and NF-kB pathways in A549 cells.

BACKGROUND: Neutrophil elastase (NE) was found to increase the respiratory mucin gene, MUC5AC, although the molecular mechanisms of this process remain unknown. We attempted to determine the signal transduction pathway through which NE induces MUC5AC gene expression in bronchial epithelial cells. METHODS: A fragment of 1.3 Kb MUC5AC promoter which had been cloned into the pGL3-Basic luciferase vector was transfected to the A549 cells. By measuring the luciferase activity, we were able to evaluate the MUC5AC promoter activity in A549 cells. The involvement of mitogen-activated protein kinases (MAPK) was confirmed by Western blotting. To confirm the involvement of nuclear factorkappaB (NF-kB), we used site-directed mutagenesis and electrophoretic mobility shift assay (EMSA) autoradiogram. The MUC5AC mRNA expression was confirmed by RT-PCR. RESULTS: NE increased the transcriptional activity of the MUC5AC promoter in A549 cells. The increased transcriptional activity of the MUC5AC promoter by NE was found to be associated with increased NF-kB activity. Site-directed mutagenesis showed that the transfection of the mutated NF-kB binding sites from the PGL3-MUC5AC-3752 promoter luciferase reporter plasmid decreased the luciferase activity after NE stimulation. Among the MAPKs, only extracellular signal-regulated kinases (ERK) were involved in this NE-induced MUC5AC mucin expression. RT-PCR also showed that NE increased MUC5AC mRNA. An EMSA autoradiogram revealed that NE induced NF-kB:DNA binding. CONCLUSIONS: These results indicate that human NE induces MUC5AC mucin through the epidermal growth factor receptor (EGF-R), ERK, and NF-kB pathways in A549 cells.

The role of nitric oxide in the particulate matter (PM2.5)-induced NFkappaB activation in lung epithelial cells.

NFkappaB is one of key transcription factors that are involved in the inflammatory responses to the particulate matter (PM) in the lungs. In order to further understand the molecular mechanism, the effects of antioxidants and an inducible nitric oxide synthase (iNOS) inhibitor on PM-induced NFkappaB activation were examined in A549 lung epithelial cells. NFkappaB activation by 2.5 microm particulates (PM2.5) was evident from the degradation of an NFkappaB inhibitory protein, IkappaBalpha, and a luciferase reporter assay for NFkappaB activity. In these experiments, a pre-treatment of the cells with antioxidants N-acetyl-l-cysteine (NAC) and dimethylthiourea (DMTU) or an iNOS inhibitor l-N6-1-iminoethyl-lysine (L-NIL) clearly inhibited the NFkappaB activation by PM2.5. The inhibitory effect of L-NIL was also observed on the PM2.5-induced interleukin-8 (IL-8) gene expression both at the transcriptional and protein levels. These results suggest that PM2.5 induces NFkappaB activity via the pathways involving ROS and/or RNS generation. Considering the fact that NFkappaB also induces NO generation via iNOS expression, they might make a positive feedback loop that amplifies the downstream responses.