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A 24-year-old man with a history of bloody sputum for 6 months was referred to our hospital with suspected alveolar hemorrhaging due to vasculitis. Chest computed tomography showed ground-glass opacities in both lungs, and an examination of his bronchoalveolar lavage fluid showed alveolar hemorrhaging. However, no evidence of vasculitis was found, and subsequent polysomnographic testing confirmed that he had severe obstructive sleep apnea (OSA). Since the alveolar hemorrhaging improved after the initiation of continuous positive airway pressure treatment, the diagnosis was negative-pressure alveolar hemorrhaging due to severe OSA.

Das kleinzellige Lungenkarzinom (small-cell lung cancer, SCLC) reagiert sehr empfindlich auf eine platinbasierte Chemotherapie. Bei Patienten, die bei der Erstdiagnose einen schlechten Performance-Status (PS) aufweisen, ist die Indikation jedoch umstritten. In der vorliegenden Arbeit überprüften wir retrospektiv alle klinischen Verläufe von Patienten mit histopathologisch gesichertem SCLC und schlechtem Performance-Status, das heißt PS 3 und 4 gemäß Eastern Cooperative Oncology Group. Von 18 Patienten erhielten 12 eine Chemotherapie und 6 lediglich eine supportive Therapie. Unter den Chemotherapie-Zyklen kam es bei 7 Patienten (58,3%, einschließlich der PS-4-Fälle) zu einer Verbesserung des Performance-Status, bei 2 Patienten (16,7%) blieb er stabil und bei 3 Patienten (25%) verschlechterte er sich. Darüber hinaus zeigten 5 Patienten ein partielles Ansprechen auf die Chemotherapie (Ansprechrate von 41,7%). Zehn (10) Patienten (83,3%) entwickelten eine Neutropenie Grad 3 bis 4 und bei 5 Patienten (41,7%) trat eine febrile Neutropenie Grad 3 auf; eine nicht-hämatologische Toxizität Grad 4 wurde nicht festgestellt. Ein 77-jähriger männlicher Patient mit PS 3 verstarb infolge einer behandlungsbedingten Lungentoxizität (Grad 5). Es zeigte sich kein wesentlicher Unterschied in der Überlebensdauer zwischen Patienten mit PS 3 und PS 4, selbst dann nicht, wenn Patienten, die lediglich eine supportive Therapie erhalten hatten, in die Analyse einbezogen wurden. Die Behandlung hatte einen positiven Effekt auf das Überleben: Nach der Chemotherapie lag die 6-Monats-Überlebensrate der Patienten mit PS 3 und 4 bei 66,7%. Demgegenüber starben alle Patienten, die nur eine supportive Therapie erhalten hatten, innerhalb von 5 Monaten. Diese Ergebnisse sprechen dafür, dass eine Chemotherapie nicht nur bei ausgewählten SCLC-Patienten mit PS 3, sondern auch solchen mit PS 4 indiziert ist.

Elongation of very-long-chain fatty acids protein 6 (ELOVL6), an enzyme regulating elongation of saturated and monounsaturated fatty acids with C12-C16 to those with C18, has been recently indicated to affect various immune and inflammatory responses; however, the precise process by which ELOVL6-related lipid dysregulation affects allergic airway inflammation is unclear.To evaluate the biological roles of ELOVL6 in allergic airway responses and investigate whether regulating lipid composition in the airways could be an alternative treatment for asthma.Expressions of ELOVL6 and other isoforms were examined in the airways of severely asthmatic patients and mouse models of asthma. Wild-type (WT) and ELOVL6-deficient (Elovl6ELOVL6 expression was downregulated in the bronchial epithelium of severely asthmatic patients compared with controls. In asthmatic mice, ELOVL6 deficiency led to enhanced airway inflammation in which lymphocyte egress from lymph nodes was increased, and both type 2 and non-type 2 immune responses were upregulated. Lipidomic profiling revealed that the levels of palmitic acid, ceramides and sphingosine-1-phosphate (S1P) were higher in the lungs of OVA-immunized Elovl6This study illustrates a crucial role for ELOVL6 in controlling allergic airway inflammation via regulation of fatty acid composition and ceramide-S1P biosynthesis, and indicates that ELOVL6 may be a novel therapeutic target for asthma.

The programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) pathway could affect antimicrobial immune responses by suppressing T cell activity. Several recent studies demonstrated that blocking of the PD-1/PD-L1 pathway exacerbated Mycobacterium tuberculosis infection. However, the effect of blocking this pathway in pulmonary Mycobacterium avium–intracellulare complex (MAC) infection is not fully understood. Wild-type, PD-1-deficient mice, and PD-L1-deficient mice were intranasally infected with Mycobacterium avium bacteria. Depletion of PD-1 or PD-L1 did not affect mortality and bacterial burden in MAC-infected mice. However, marked infiltration of CD8-positive T lymphocytes was observed in the lungs of PD-1 and PD-L1-deficient mice compared to wild-type mice. Comprehensive transcriptome analysis showed that levels of gene expressions related to Th1 immunity did not differ according to the genotypes. However, genes related to the activity of CD8-positive T cells and related chemokine activity were upregulated in the infected lungs of PD-1 and PD-L1-deficient mice. Thus, the lack of change in susceptibility to MAC infection in PD-1 and PD-L1-deficient mice might be explained by the absence of obvious changes in the Th1 immune response. Furthermore, activated CD8-positive cells in response to MAC infection in these mice seemed to not be relevant in the control of MAC infection.

Epithelial-mesenchymal transition (EMT) is a cellular process by which epithelial cells transform to acquire mesenchymal phenotypes. Accumulating evidence indicate the involvement of EMT in the progression of malignant diseases. Notch signaling mediates TGF-β1-induced EMT through direct transcriptional activation of Snai1. The molecular mechanism how TGF-β1 activates Notch signaling, however, remains unknown. In this study, we show a pivotal role for reactive oxygen species (ROS)-Nrf2 pathway in TGF-β1-induced Notch signaling activation and EMT development. TGF-β1 induces Nrf2 activation through ROS production. Inhibiting Nrf2 activation either by reducing ROS levels by N-acetylcysteine or by knocking down of Nrf2 by small interfering RNA attenuated both Notch signaling activation and EMT development. TGF-β1 induced the transcription of Notch4 via Nrf2-dependent promoter activation. In conclusion, our study indicates the ROS-Nrf2 pathway mediates the development of TGF-β1-induced EMT through the activation of Notch signaling.

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized by peripheral airways inflammation and emphysema. Emerging evidence indicates a contribution of both innate and adaptive immune cells to the development of COPD. Transcription factor T-bet modulates the function of immune cells and therefore might be involved in the pathogenesis of COPD. To elucidate the role for T-bet in elastase-induced emphysema, pathological phenotypes were compared between wild-type and T-bet-/- mice. T-bet-/- mice demonstrated enhanced emphysema development on histological analyses, with higher values of mean linear intercept and dynamic compliance relative to wild-type mice. The number of neutrophils in BAL fluids, lung IL-6 and IL-17 expression, and the proportion of CD4+ T cells positive for IL-17 or retinoic acid receptor-related orphan receptor-γt were higher in T-bet-/- mice than in wild-type mice. Although T-bet downregulates cytokine expression in bone marrow-derived macrophages and MH-S cells, a murine alveolar cell line, depending on the surrounding environment, IL-6 expression in alveolar macrophages isolated from elastase-treated mice was not dependent on T-bet. Coculture of bone marrow-derived macrophages and CD4+ T cells revealed that T-bet regulation of IL-17 expression was dependent on CD4+ T cells. Neutralizing antibodies against IL-6R or IL-17 ameliorated the development of emphysema in T-bet-/- mice. In conclusion, we demonstrate that T-bet ameliorates elastase-induced emphysema formation by modulating the host immune response in the lungs.

Small-cell lung cancer (SCLC) is highly sensitive to platinum-based chemotherapy. However, its indication in patients with a poor performance status (PS) at initial diagnosis is controversial. We retrospectively reviewed all clinical courses of pathologically diagnosed SCLC patients with poor PS, Eastern Cooperative Oncology Group PS 3 and 4. Among 18 patients, 12 were treated with chemotherapy and 6 with supportive care alone. During the chemotherapy courses, PS improved in 7 (58.3%, including the PS 4 cases), remained stable in 2 (16.7%), and deteriorated in 3 (25%) patients. Moreover, 5 patients showed partial responses to chemotherapy (response rate of 41.7%). Grade 3-4 neutropenia developed in 10 (83.3%) patients and grade 3 febrile neutropenia occurred in 5 (41.7%) patients, but no grade 4 non-hematological toxicity was noted. Mortality associated with lung toxicity (grade 5) due to treatment occurred in a 77-year-old-male patient with PS 3. No substantial difference in survival was observed between patients with PS 3 and 4, even when including those treated with supportive care alone. Treatment had a positive effect on survival: after chemotherapy, the 6-month survival rate of PS 3 and 4 patients was 66.7%. In contrast, all patients treated with supportive care alone died within 5 months. These findings suggest that chemotherapy is indicated in selected SCLC patients not only with PS 3, but also with PS 4. (C) 2019 The Author(s) Published by S. Karger AG, Basel

Pasteurella multocida, which colonizes upper respiratory and digestive tracts, is a leading cause of respiratory diseases in many host species. Here, we describe a case of P. multocida pneumonia with hemoptysis. A 72-year-old female diagnosed with bronchiectasis with a 36-year history presented with a worsened infiltrative and granular shadow in the lower right lobe and lingular segment. Bronchial lavage fluid culturing suggested Pasteurella pneumonia. P. multocida was confirmed by 16S rRNA sequencing. The patient was readmitted to our hospital because of hemoptysis, and she was treated successfully with antibiotic therapy. The possibility of P. multocida infection must be considered in patients who own pets. Keywords: Pasteurella multocida, Pasteurella canis, Hemoptysis, Pasteurellosis

Oxidative stress induced by cigarette smoke and other environmental pollutants contributes to refractory asthma. To better understand the role of smoking in asthma, we investigated the effects of cigarette smoke on allergic airway responses in mice and examined expression of nuclear factor-E2-related factor-2 (Nrf2) and its downstream factors, because Nrf2 is known to play a pivotal role in antioxidant responses. OVA-sensitized and challenged BALB/c mice were exposed to cigarette smoke and then treated with dexamethasone, sulforaphane (an activator of Nrf2), or their combination. Upon exposure to cigarette smoke, Nrf2 and associated transcripts were upregulated in response to oxidative stress, and asthmatic responses were steroid resistant. In OVA-sensitized and challenged mice exposed to cigarette smoke and treated with sulforaphane, Nrf2-mediated antioxidant responses were upregulated to a greater extent, and steroid sensitivity of asthmatic responses was restored. Moreover, the expression and activity of histone deacetylase 2 (HDAC2), a key regulator of steroid responsiveness, was reduced in mice exposed to cigarette smoke, but restored by sulforaphane treatment. No effects of sulforaphane were observed in Nrf2-deficient mice. These findings indicate that cigarette smoke induces steroid unresponsiveness in asthmatic airways, and that sulforaphane restores steroid sensitivity via upregulation of Nrf2 and enhancement of HDAC2 expression and activity. Thus, Nrf2 may serve as a potential molecular target for cigarette smoke-related refractory asthma resistant to steroid therapy.

Nontuberculous mycobacteria (NTM) are an important cause of morbidity and mortality in pulmonary infections. Among them, Mycobacterium avium complex (MAC) is the most common cause of pulmonary NTM disease worldwide., Nrf2 is a redox-sensitive transcription factor that is thought to be important in protection against intracellular pathogens. To determine the protective role of Nrf2 in the host defense against Mycobacterium avium complex (MAC), both wild-type and Nrf2-deficient mice were intranasally infected with MAC bacteria. Nrf2-deficient mice were highly susceptible to MAC bacteria compared with wild-type mice. There were no significant changes in the levels of oxidative stress and Th1 cytokine production between genotypes. Comprehensive transcriptome analysis showed that the expressions of Nramp1 and HO-1 were much lower in the infected lungs, and the expression of Nramp1 was especially lower in alveolar macrophages of Nrf2-deficient mice than of wild-type mice. Electron microscopy showed that many infected alveolar macrophages from Nrf2-deficient mice contained a large number of intracellular MAC bacteria with little formation of phagolysosomes, compared with those from wild-type mice. Treatment with sulforaphane, an activator of Nrf2, increased resistance to MAC with increased lung expression of Nramp1 and HO-1 in wild-type mice. These results indicate that Nramp1 and HO-1, regulated by Nrf2, are essential in defending against MAC infection due to the promotion of phagolysosome fusion and granuloma formation, respectively. Thus, Nrf2 is thought to be a critical determinant of host resistance to MAC infection.

Among the dysfunctions and pathologies associated with sepsis, the underlying molecular mechanisms of sepsis-induced acute lung injury (ALI) are poorly understood. Endothelin (ET)-1, a potent vasoconstrictor and pro-inflammatory peptide, is known to be involved in the pathogenesis of ALI in a rat model of sepsis. Here, we investigated whether landiolol hydrochloride, an ultra-short-acting β-blocker, plays a crucial role in ameliorating and attenuating LPS-induced ALI through modulation of the ET-1 system. Male Wistar rats at 8 weeks of age were administered with either saline or lipopolysaccharide (LPS) for three hours (3 h) and some of the LPS-administered rats were continuously treated with landiolol for 3 h. ALI was induced by LPS, including levels of both circulatory and pulmonary TNF-α and IL-6 but [PaO2] was significantly decreased. LPS also induced a significant increase in levels of pulmonary ET-1 and ET-A receptor, but levels of ET-B receptor, which has vasodilating effects, were remarkably diminished. Further, LPS administration upregulated the pulmonary expression of HIF-1α. Finally, the treatment of LPS-administered rats with landiolol for 3 h ameliorated and prevented ALI, normalized the altered levels of pulmonary ET-1 and ET-A receptors. Landiolol also induced significant down-regulation of ET-B receptor in lung tissues in the early hours (phase) of sepsis. However, Landiolol treatment had no effect on the up-regulated inflammatory mediators (TNF-α, IL-6) in both plasma and lung tissues during sepsis, and expression of pulmonary HIF-1α also remained unchanged after landiolol treatment. Collectively, these data led us to conclude that landiolol may ameliorate sepsis-induced ALI via the pulmonary ET system.

Siglec-F is a pro-apoptotic receptor on mouse eosinophils that recognizes 6′-sulfated sialyl Lewis X and 6′-sulfated sialyl N-acetyl-lactosamine as well as multivalent sialyl N-acetyl-lactosamine structures on glycan arrays. We hypothesized that attenuation of the carbohydrate sulfotransferase 1 (CHST1) gene encoding keratan sulfate galactose 6-O-sulfotransferase, an enzyme likely required for 6′-sulfation of some of these putative Siglec-F glycan ligands, would result in decreased Siglec-F lung ligand levels and enhanced allergic eosinophilic airway inflammation. Tissue analysis detected CHST1 expression predominantly not only in parenchymal cells but not in airway epithelium, the latter being a location where Siglec-F ligands are located. Western blotting of lung extracts with Siglec-F–Fc fusion proteins detected ≈500 kDa and ≈200 kDa candidate Siglec-F ligands that were not appreciably altered in CHST1(−)(/)(−) lungs compared with normal mouse lungs. Characterization of the O-linked glycans of lung tissue and bronchoalveolar lavage fluid detected altered sialylation but minimal change in sulfation. Eosinophilic airway inflammation was induced in wild-type (WT) and CHST1(−)(/)(−) mice via sensitization to ovalbumin (OVA) and repeated airway challenge. After OVA sensitization and challenge, Siglec-F ligands on airway cells, and numbers of eosinophils and neutrophils accumulating in the airways, both increased to a similar degree in WT and CHST1(−)(/)(−) mouse lungs, while macrophages and lymphocytes increased significantly more in CHST1(−)(/)(−) mouse airway compared with normal mouse lungs. Therefore, keratan sulfate galactose 6-O-sulfotransferase does not contribute to the synthesis of glycan ligands for Siglec-F in the airways, although its absence results in exaggerated accumulation of airway macrophages and lymphocytes.

Paraneoplastic limbic encephalitis (PLE), a paraneoplastic neurological syndrome (PNS), is a rare nervous system disorder that results from the indirect effects of tumors and is commonly associated with small-cell lung cancer (SCLC). Previous studies have reported that magnetic resonance imaging (MRI) may be useful for diagnosing LE. Temporal lobe abnormalities are observed using T2-weighted and fluid-attenuated inversion recovery sequences; however, such abnormalities are detected in only 60% of patients with PLE. The present study describes a case of PLE associated with SCLC, in which LE was observed using MRI 26 days after the first convulsive seizure. Although the serum and cerebrospinal fluid analyses for onconeural antibodies were negative, the findings of this case indicate that PLE should be considered in the differential diagnosis, and that repeated brain MRI may be more helpful for diagnosis, as the brain MRI findings may be normal during the early stages of PLE.

Apoptosis is a physiological process that plays a critical maintenance role in cellular homeostasis. Previous reports have demonstrated that cells undergo apoptosis in a cell density-dependent manner, which is regulated, in part, by signal transducers and activators of transcription (STAT) 3. The molecular mechanisms regulating cell density-dependent apoptosis, however, has not been thoroughly investigated to date. Since Notch signaling is activated via direct cell-to-cell contact and plays a pivotal role in cell fate decisions, we examined the role of Notch signaling in cell density-dependent apoptosis of mouse embryonic fibroblasts NIH 3T3 cells. With the increase in cell density, IL-6 expression was induced, which was necessary for STAT3 activation as well as apoptosis regulation. Notch signaling was also activated in a cell-density dependent manner. Blocking Notch signaling either through siRNA-mediated targeting of Jagged1 expression or γ-secretase inhibitor treatment demonstrated that Notch signaling activation was necessary for IL-6 induction. Constitutive activation of Notch signaling via the overexpression of Notch1 intracellular domain was sufficient for the induction of IL-6, which was mediated via direct transcriptional activation. Taken together, our study indicates that Notch signaling regulates cell density-dependent apoptosis through IL-6/STAT3-dependent mechanism. Consequently, Notch signaling might represent a novel therapeutic target in diseases characterized by dysregulated apoptosis.

Siglec-8 and Siglec-F are single pass transmembrane inhibitory receptors found on the surface of human and mouse eosinophils, respectively, but very little is known about their physiologic glycan ligands. This article reviews the latest knowledge on this topic and outlines the strategies being used to further define the production and glycobiochemical nature of these molecules in the lung.Both Siglec-8 and Siglec-F recognize the same glycan structure, namely 6'-sulfated sialyl Lewis X, as determined using glycan array technologies. Studies have identified α2,3-linked sialylated glycoprotein structures localized to mouse airway epithelium in tissue sections, where their constitutive expression requires the specific sialyltransferase St3gal3. Expression of these ligands in lung is enhanced during allergic inflammation and by cytokines such as IL-13, and is maintained in primary air-liquid interface cultures of mouse lung epithelium. Further characterization suggests that they are high molecular weight sialylated proteins, putatively mucins. By combining analytic glycomics, glycoproteomic mapping, and further in-vitro eosinophil experimentation including the ability of candidate structures to enhance eosinophil apoptosis, a finely detailed appreciation of the structural requirements for productive Siglec-8 and Siglec-F engagement should soon emerge.An enhanced understanding of Siglec-F, Siglec-8, and their ligands should improve our understanding of endogenous lung pathways limiting the survival of eosinophils within the airway in diseases such as asthma. Knowledge of this biology may also result in novel opportunities for drug development involving glycans and glycomimetics that selectively bind to Siglec-8 and induce eosinophil death.

Siglecs (sialic acid immunoglobulin-like lectins) are members of the immunoglobulin gene family that contain sialoside binding N-terminal domains. They are cell surface proteins found predominantly on cells of the immune system. Among them, Siglec-8 is uniquely expressed by human eosinophils and mast cells, as well as basophils. Engaging this structure with antibodies or glycan ligands results in apoptosis in human eosinophils and inhibition of release of preformed and newly generated mediators from human mast cells without affecting their survival. Pro-apoptotic effects are also seen when its closest functional paralog, Siglec-F, on mouse eosinophils is similarly engaged in vitro, and beneficial effects are observed after administration of Siglec-F antibody using models of eosinophilic pulmonary and gastrointestinal inflammation in vivo. Siglec-8 targeting may thus provide a means to specifically inhibit or deplete these cell types. Cell-directed therapies are increasingly sought after by the pharmaceutical industry for their potential to reduce side effects and increase safety. The challenge is to identify suitable targets on the cell type of interest, and selectively deliver a therapeutic agent. By targeting Siglec-8, monoclonal antibodies and glycan ligand-conjugated nanoparticles may be ideally suited for treatment of eosinophil and mast cell-related diseases, such as asthma, chronic rhinosinusitis, chronic urticaria, hypereosinophilic syndromes, mast cell and eosinophil malignancies and eosinophilic gastrointestinal disorders.

Summary Background We demonstrated previously that GATA-3 overexpression markedly enhanced allergen-induced airway inflammation and airway remodelling, including subepithelial fibrosis, and smooth muscle cell hyperplasia, in transgenic mice. Objective Because cysteinyl leukotrienes (cysLTs) have been shown to be involved in such structural changes, the effects of a specific cysLT1 receptor antagonist, montelukast, were evaluated in a mouse model of chronic asthma. Methods GATA-3-overexpressing mice and wild-type Balb/c mice were sensitized and repeatedly challenged by ovalbumin (OVA) or saline. The effects of montelukast on the development of airway remodelling were compared between the two mouse genotypes. Results CysLTs in the lung were increased after repeated allergen challenges, and significantly enhanced in GATA-3-overexpressing mice. The enhanced cysLT levels were accompanied by the development of eosinophilia, smooth muscle cell hyperplasia, and increased stromal cell-derived factor-1 gene expression with a small increase in pro-collagen gene expression in OVA-challenged GATA-3-overexpressing mice, but not in wild-type mice. Montelukast significantly decreased lung cysLT levels and inhibited the GATA-3-overexpression-related airway remodelling, potently preventing smooth muscle cell hyperplasia, but partially suppressed the increased pro-collagen gene expression and eosinophilic inflammation. Increases in the levels of IL-4, IL-5, IL-13, and eotaxin in bronchial lavage and TGF-β gene expression in the lungs were induced by OVA in both mouse genotypes. Montelukast treatment also significantly reduced these levels to the levels seen after saline challenges in GATA-3-overexpressing mice. Conclusion Montelukast efficaciously prevented airway inflammation and remodelling in a GATA-3-overexpression antigen challenge mouse model by decreasing the cysLT-driven Th2 cytokine cycle of amplification of airway pathologies. Cite this as: T. Kiwamoto, Y. Ishii, Y. Morishima, K. Yoh, N. Kikuchi, N. Haraguchi, H. Masuko, M. Kawaguchi, A. Nomura, T. Sakamoto, S. Takahashi and N. Hizawa, Clinical & Experimental Allergy, 2011 (41) 116–128.

Hypersensitivity pneumonitis (HP) is mediated by a Th1 immune response. Transcription factor GATA binding protein-3 (GATA-3) is believed to be a key regulator of Th2 differentiation and thus might play regulatory roles in the pathogenesis of hypersensitivity pneumonitis (HP).We examined the effect of GATA-3 overexpression on the development of HP in mice.Wild-type C57BL/6 mice and GATA-3-overexpressing mice of the same background were used in this study. HP was induced by repeated exposure to Saccharopolyspora rectivirgula, the causative antigen of farmer's lung.Antigen exposure resulted in a marked inflammatory response with enhanced pulmonary expression of T-bet and the Th1 cytokine interferon (IFN)-gamma in wild-type mice. The degree of pulmonary inflammation was much less severe in GATA-3-overexpressing mice. The induction of T-bet and IFN-gamma genes was suppressed, but a significant induction of Th2 cytokines, including IL-5 and IL-13, was observed in the lungs of GATA-3-overexpressing mice after antigen exposure. Supplementation with recombinant IFN-gamma enhanced lung inflammatory responses in GATA-3-overexpressing mice to the level of wild-type mice. Because antigen-induced IFN-gamma production predominantly occurred in CD4+ T cells, nude mice were transferred with CD4+ T cells from either wild-type or GATA-3-overexpressing mice and subsequently exposed to antigen. Lung inflammatory responses were significantly lower in nude mice transferred with CD4+ T cells from GATA-3-overexpressing mice than in those with wild-type CD4+ T cells, with a reduction of lung IFN-gamma level.These results indicate that overexpression of GATA-3 attenuates the development of HP by correcting the Th1-polarizing condition.

Background Cigarette smoke induces bronchial mucus secretion. However, the mechanism of this induction is still unidentified. In this study, we investigated the role of the putative calcium-activated chloride channel 1 (CLCA1) and its blocker, niflumic acid, in cigarette smoke-induced mucin synthesis both in vivo and in vitro. Methods and results Sprague-Dawley rats were exposed to cigarette smoke for 4 weeks. The CLCA1, epidermal growth factor receptor (EGFR), and MUC5AC expressions were increased in the trachea and lung tissues. Goblet-cell hyperplasia with marked mucin staining was detected in the tracheal and bronchial epithelium. In the human bronchial epithelial cell line NCI-H292, cigarette smoke solution also induced mucin production as well as the RNA and protein expressions of CLCA1, EGFR, and MUC5AC. Both in vivo and in vitro, the induction of MUC5AC and mucin synthesis were inhibited by niflumic acid, and/or a selective EGFR tyrosine kinase inhibitor, AG-1478. Niflumic acid also blocked the epidermal growth factor-induced MUC5AC and mucin staining in the NCI-H292 cell line. Conclusion Both EGFR and niflumic acid-sensitive chloride channels (probably CLCA1) are dependently affecting the mucin production as a part of a single complex signaling pathway. CLCA1 may be a key signaling member that can be targeted with pharmacologic interventions to treat mucus hypersecretion.

Recent studies have demonstrated that Th2 cytokines, such as interleukin-4 and interleukin-13, enhance fibrotic processes by activating fibroblast proliferation and collagen production, whereas interferon-gamma, a Th1 cytokine, inhibits these processes. Th1 and Th2 cells both differentiate from common T precursor cells, with transcription factor GATA-3 a key regulator of Th2 differentiation. In the present study, therefore, we examined the effects of GATA-3 overexpression on the development of pulmonary fibrosis in a mouse model. Wild-type C57BL/6 mice and GATA-3-overexpressing (GATA-3-tg) mice of the same background were intratracheally treated with bleomycin. The survival rate after bleomycin was significantly decreased in GATA-3-tg mice compared with wild-type mice. The degree of pulmonary fibrosis was much greater in GATA-3-tg mice than in wild-type mice 28 days after bleomycin treatment. Lung interferon-gamma concentration was significantly decreased in GATA-3-tg mice compared with wild-type mice by 7 days after either saline or bleomycin treatment. The concentration of transforming growth factor-beta, a fibrogenic cytokine, was significantly higher in GATA-3-tg mice than in wild-type mice. Exogenous administration of interferon-gamma to GATA-3-tg mice improved the degree of pulmonary fibrosis and thus increased survival. These results indicate that overexpression of GATA-3 enhances the development of pulmonary fibrosis, possibly by reducing interferon-gamma levels in the lung.

Emphysema is one of the major pathological abnormalities associated with chronic obstructive pulmonary disease. The protease/antiprotease imbalance and inflammation resulting from oxidative stress have been attributed to the pathogenesis of emphysema. Nrf2 is believed to protect against oxidative tissue damage through the transcriptional activation of a battery of antioxidant enzymes. In this study, we investigated the protective role of Nrf2 in the development of emphysema using elastase-induced emphysema as our model system. We found that elastase-provoked emphysema was markedly exacerbated in Nrf2-knockout (KO) mice compared with wild-type mice. The severity of emphysema in Nrf2-KO mice correlated intimately with the degree of lung inflammation in the initial stage of elastase treatment. The highly inducible expression of antioxidant and antiprotease genes observed in wild-type alveolar macrophages was significantly attenuated in the lungs of Nrf2-KO mice. Interestingly, transplantation of wild-type bone marrow cells into Nrf2-KO mice retarded the development of initial lung inflammation and subsequent emphysema, and this improvement correlated well with the appearance of macrophages expressing Nrf2-regulated antiprotease and antioxidant genes. Thus, Nrf2 appears to exert its protective effects through the transcriptional activation of antiprotease and antioxidant genes in alveolar macrophages.

Inflammation, protease/anti-protease imbalance and oxidative stress play important roles in the pathogenesis of emphysema. Nrf2 counteracts oxidative tissue damage and inflammation through transcriptional activation via the anti-oxidant responsive element (ARE). To clarify the protective role of Nrf2 in the development of emphysema, the susceptibility of Nrf2-knockout mice to cigarette smoke (CS)-induced emphysema was examined. In Nrf2-knockout mice, emphysema was first observed at 8 weeks and exacerbated by 16 weeks following CS-exposure, whereas no pathological abnormalities were observed in wild-type mice. Neutrophilic lung inflammation and permeability lung damage were significantly enhanced in Nrf2-knockout mice 8 weeks after CS-exposure. Importantly, neutrophil elastase activity in bronchoalveolar lavage fluids was markedly higher in Nrf2-knockout mice preceding the pronounced neutrophil accumulation. The expression of secretory leukoprotease inhibitor, a potent inhibitor of neutrophil elastase, was inducible in wild-type, but not in Nrf2-knockout mice. This protease/anti-protease imbalance, together with the lack of inducible expression of ARE-regulated anti-oxidant/anti-inflammatory genes, may explain the predisposition of Nrf2-knockout mice to neutrophilic inflammation. Indeed, specific activators of Nrf2 induced the expression of the SLPI gene in macrophages. These results indicate that Nrf2 protects against the development of emphysema by regulating not only the oxidant/anti-oxidant balance, but also inflammation and the protease/anti-protease balance.

To clarify the essential role of NKT cells in allergy, we investigated the contribution of NKT cells to the pathogenesis of eosinophilic airway inflammation using α-galactosylceramide (α-GalCer), a selective ligand for NKT cells. Although continuous administration of α-GalCer during ovalbumin (OVA) sensitization increased OVA-specific IgE levels and worsened eosinophil inflammation, a single administration of α-GalCer at the time of OVA challenge completely prevented eosinophilic infiltration in wild-type mice. This inhibitory effect of α-GalCer was associated with a decrease in airway hyperresponsiveness, an increase in IFN-γ, and decreases in IL-4, IL-5 and IL-13 levels in the bronchoalveolar lavage fluids. Analysis of lung lymphocytes revealed that production of IFN-γ increased in NK cells, but not in T or NKT cells, following α-GalCer administration. Induction of vascular cell adhesion molecule-1 in the lungs of wild-type mice was also significantly attenuated by treatment with α-GalCer. These effects of α-GalCer were abrogated in Jα281–/– mice, which lack NKT cells, and in wild-type mice treated with anti-IFN-γ Ab. Hence, our data indicate that α-GalCer suppresses allergen-induced eosinophilic airway inflammation, possibly by inducing a Th1 bias that results in inhibition of eosinophil adhesion to the lung vessels. See accompanying commentary: http://dx.doi.org/10.1002/eji.200535425

We report one Japanese familial line in which there were three pulmonary MAC patients and one suspected patient over two generations, most of whom were diagnosed with the nodular/bronchiectatic type. In all patients, life circumstances and bacterial strains differed at the time of diagnosis. This suggests that the genes thought to affect patient susceptibility to pulmonary MAC disease may be involved in this family line. Comprehensive genotypic analysis of the CFTR gene, HLA typing, and analysis of the NRAMP1 polymorphisms were performed in seven members of this family. The results suggest that female sex and menopause might be associated with onset of pulmonary MAC of the nodular/bronchiectatic type, and HLA-A26 antigen and diabetes mellitus might be involved in disease exacerbations.

Cigarette smoke induces bronchial mucus secretion. However, the mechanism of this induction is still unidentified. In this study, we investigated the role of the putative calcium-activated chloride channel 1 (CLCA1) and its blocker, niflumic acid, in cigarette smoke-induced mucin synthesis both in vivo and in vitro.Sprague-Dawley rats were exposed to cigarette smoke for 4 weeks. The CLCA1, epidermal growth factor receptor (EGFR), and MUC5AC expressions were increased in the trachea and lung tissues. Goblet-cell hyperplasia with marked mucin staining was detected in the tracheal and bronchial epithelium. In the human bronchial epithelial cell line NCI-H292, cigarette smoke solution also induced mucin production as well as the RNA and protein expressions of CLCA1, EGFR, and MUC5AC. Both in vivo and in vitro, the induction of MUC5AC and mucin synthesis were inhibited by niflumic acid, and/or a selective EGFR tyrosine kinase inhibitor, AG-1478. Niflumic acid also blocked the epidermal growth factor-induced MUC5AC and mucin staining in the NCI-H292 cell line.Both EGFR and niflumic acid-sensitive chloride channels (probably CLCA1) are dependently affecting the mucin production as a part of a single complex signaling pathway. CLCA1 may be a key signaling member that can be targeted with pharmacologic interventions to treat mucus hypersecretion.

Background Sialic acid–binding, immunoglobulin-like lectin (Siglec) F is a glycan-binding protein selectively expressed on mouse eosinophils. Its engagement induces apoptosis, suggesting a pathway for ameliorating eosinophilia in the setting of asthma and other eosinophil-associated diseases. Siglec-F recognizes sialylated sulfated glycans in glycan-binding assays, but the identities of endogenous sialoside ligands and their glycoprotein carriers in vivo are unknown. Objectives To use mouse lung-derived materials to isolate, biochemically identify, and biologically characterize naturally occurring endogenous glycan ligands for Siglec-F. Methods Lungs from normal and mucin-deficient mice, as well as mouse tracheal epithelial cells, were investigated in vitro and in vivo for the expression of Siglec-F ligands. Western blotting and cytochemistry used Siglec-F-Fc as a probe for directed purification, followed by liquid chromatography–tandem mass spectrometry of recognized glycoproteins. Purified components were tested in mouse eosinophil-binding assays and flow cytometry–based cell death assays. Results We detected mouse lung glycoproteins that bound to Siglec-F; binding was sialic acid dependent. Proteomic analysis of Siglec-F binding material identified Muc5b and Muc4. Cross-affinity enrichment and histochemical analysis of lungs from mucin-deficient mice assigned and validated the identity of Muc5b as one glycoprotein ligand for Siglec-F. Purified mucin preparations carried sialylated and sulfated glycans, bound to eosinophils and induced their death in vitro . Mice conditionally deficient in Muc5b displayed exaggerated eosinophilic inflammation in response to intratracheal installation of IL-13. Conclusions These data identify a previously unrecognized endogenous anti-inflammatory property of airway mucins by which their glycans can control lung eosinophilia through engagement of Siglec-F.