Identification of Siglec-1-negative alveolar macrophages with proinflammatory phenotypes in chronic obstructive pulmonary disease.

Alveolar macrophages (AMs) in patients with chronic obstructive pulmonary disease (COPD) orchestrate persistent inflammation in the airway. However, subpopulations of AMs participating in chronic inflammation have been poorly characterized. We previously reported that Siglec-1 expression on AMs, which is important for bacteria engulfment, was decreased in COPD. Here, we show that Siglec-1-negative AMs isolated from COPD lung tissues exhibit a proinflammatory phenotype and are associated with poor clinical outcomes in patients with COPD. Using flow cytometry, we segregated three subsets of AMs based on the expression of Siglec-1 and their side scattergram (SSC) and forward scattergram (FSC) properties: Siglec-1+SSChiFSChi, Siglec-1-SSChiFSChi, and Siglec-1-SSCloFSClo subsets. The Siglec-1-SSCloFSClo subset number was increased in COPD. RNA sequencing revealed upregulation of multiple proinflammatory signaling pathways and emphysema-associated matrix metalloproteases in the Siglec-1-SSCloFSClo subset. Gene set enrichment analysis indicated that the Siglec-1-SSCloFSClo subset adopted intermediate phenotypes between monocytes and mature alveolar macrophages. Functionally, these cells produced TNF-α, IL-6, and IL-8 at baseline, and these cytokines were significantly increased in response to viral RNA. The increase in Siglec-1-negative AMs in induced sputum is associated with future exacerbation risk and lung function decline in patients with COPD. Collectively, the novel Siglec-1-SSCloFSClo subset of AMs displays proinflammatory properties, and their emergence in COPD airways may be associated with poor clinical outcomes.NEW & NOTEWORTHY Alveolar macrophages (AMs) in patients with chronic obstructive pulmonary disease (COPD) orchestrate persistent inflammation in the airway. We find that Siglec-1-negative alveolar macrophages have a wide range of proinflammatory landscapes and a protease-expressing phenotype. Moreover, this subset is associated with the pathogenesis of COPD and responds to viral stimuli.

CYP27A1-27-hydroxycholesterol axis in the respiratory system contributes to house dust mite-induced allergic airway inflammation.

BACKGROUND: 27-Hydroxycholesterol (27-HC) derived from sterol 27-hydroxylase (CYP27A1) has pro-inflammatory biological activity and is associated with oxidative stress and chronic inflammation in COPD. However, the role of regulation of CYP27A1- 27-HC axis in asthma is unclear. This study aimed to elucidate the contribution of the axis to the pathophysiology of asthma. METHODS: House dust mite (HDM) extract was intranasally administered to C57BL/6 mice and the expression of CYP27A1 in the airways was analyzed by immunostaining. The effect of pre-treatment with PBS or CYP27A1 inhibitors on the cell fraction in the bronchoalveolar lavage fluid (BALF) was analyzed in the murine model. In vitro, BEAS-2B cells were treated with HDM and the levels of CYP27A1 expression were examined. Furthermore, the effect of 27-HC on the expressions of E-cadherin and ZO-1 in the cells was analyzed. The amounts of RANTES and eotaxin from the 27-HC-treated cells were analyzed by ELISA. RESULTS: The administration of HDM increased the expression of CYP27A1 in the airways of mice as well as the number of eosinophils in the BALF. CYP27A1 inhibitors ameliorated the HDM-induced increase in the number of eosinophils in the BALF. Treatment with HDM increased the expression of CYP27A1 in BEAS-2B cells. The administration of 27-HC to BEAS-2B cells suppressed the expression of E-cadherin and ZO-1, and augmented the production of RANTES and eotaxin. CONCLUSIONS: The results of this study suggest that aeroallergen could enhance the induction of CYP27A1, leading to allergic airway inflammation and disruption of the airway epithelial tight junction through 27-HC production.

Metabolic and Epigenetic Regulation of SMAD7 by STC1 Ameliorates Lung Fibrosis.

As shown in our previous studies, the intratracheal-administration of STC1 (stanniocalcin-1) ameliorates pulmonary fibrosis by reducing oxidative and endoplasmic reticulum stress through the uncoupling of respiration in a bleomycin-treated mouse model. However, the overall effect of STC1 on metabolism was not examined. Therefore, we first conducted a comprehensive metabolomics analysis to screen the overall metabolic changes induced by STC1 in an alveolar epithelial cell line using capillary electrophoresis time-of-flight mass spectrometry. The results were subsequently validated in multiple alveolar epithelial and fibroblast cell lines by performing precise analyses of each substance. STC1 stimulated glycolysis, acetyl-CoA synthesis, and the methionine and cysteine-glutathione pathways, which are closely related to the uncoupling of respiration, modulation of epigenetics, and reduction in oxidative stress. These results are consistent with our previous study. Subsequently, we focused on the inhibitory factor SMAD7, which exerts an antifibrotic effect and is susceptible to epigenetic regulation. STC1 upregulates SMAD7 in an uncoupling protein 2-dependent manner, induces demethylation of the SMAD7 promoter region and acetylation of the SMAD7 protein in human alveolar epithelial and fibroblast cell lines and a bleomycin-treated mouse model, and subsequently attenuates fibrosis. The antifibrotic effects of STC1 may partially depend on the regulation of SMAD7. In the evaluation using lung tissue from patients with idiopathic pulmonary fibrosis, SMAD7 expression and acetylation were high in the alveolar structure-preserving region and low in the fibrotic region. The intratracheal administration of STC1 may prevent the development of pulmonary fibrosis by regulating the metabolism-mediated epigenetic modification of SMAD7 in patients.

Decreased expression of airway epithelial Axl is associated with eosinophilic inflammation in severe asthma.

BACKGROUND: Airway epithelium-derived cytokines are critical to provoke and perpetuate type 2 inflammation in asthma. Yet it is poorly understood how this epithelial cell-driven inflammatory response is negatively regulated. We previously reported that Axl receptor tyrosine kinase was expressed by basal cells in the airway epithelium and had a role in defining their stem cell identity. However, whether and how Axl regulates airway type 2 inflammation remains unknown. METHODS: We performed immunofluorescence staining to compare Axl expression in airway epithelium between non-asthmatic subjects, mild-moderate asthma and severe asthma. We confirmed this result by interrogating public databases of global gene expression in endobronchial biopsies. We then quantified eosinophil numbers infiltrating into the trachea of wild-type or Axl-knockout mice that were intranasally treated with house dust mite extracts (HDM). Cell-based assays using siRNA targeting Axl were further performed to identify molecules involved in Axl-mediated regulation of inflammation. RESULTS: Histological assessments and transcriptome analyses revealed decreases in protein and mRNA of Axl in airway basal cells of severe asthmatics. This reduction of Axl expression was correlated with infiltration of eosinophils and mast cells in severe asthmatics. Eosinophil infiltration was more evident in the trachea of Axl-knockout mice in response to repetitive HDM administration. siRNA-mediated knockdown of Axl increased mRNA and protein expression of granulocyte macrophage-colony stimulating factor (GM-CSF) in human bronchial epithelial cells. CONCLUSIONS: Axl kinase expressed by basal cells may suppress excessive eosinophilic inflammation via inhibition of GM-CSF in the airway. Axl reduction has clinical implications for the pathogenesis of severe asthma.

Upregulation of leukocyte immunoglobulin-like receptor B4 on interstitial macrophages in COPD; their possible protective role against emphysema formation.

BACKGROUND: Leukocyte immunoglobulin-like receptor B4 (LILRB4) is one of the inhibitory receptors in various types of immune cells including macrophages. Previous reports suggested that LILRB4 could be involved in a negative feedback system to prevent excessive inflammatory responses. However, its role has been unclear in chronic obstructive pulmonary disease (COPD), in which macrophages play a crucial role in the pathogenesis. In this study, we aimed to examine the changes of LILRB4 on macrophages both in the lung specimens of COPD patients and the lungs of a mouse emphysema model. We then tried to compare the differences in both inflammation and emphysematous changes of the model between wild-type and LILRB4-deficient mice in order to elucidate the role of LILRB4 in the pathogenesis of COPD. METHODS: We prepared single-cell suspensions of resected lung specimens of never-smokers (n = 21), non-COPD smokers (n = 16), and COPD patients (n = 14). The identification of LILRB4-expressing cells and the level of LILRB4 expression were evaluated by flow cytometry. We analyzed the relationships between the LILRB4 expression and clinical characteristics including respiratory function. In the experiments using an elastase-induced mouse model of emphysema, we also analyzed the LILRB4 expression on lung macrophages. We compared inflammatory cell accumulation and emphysematous changes induced by elastase instillation between wild-type and LILRB4-deficient mice. RESULTS: The levels of surface expression of LILRB4 are relatively high on monocyte linage cells including macrophages in the human lungs. The percentage of LILRB4+ cells in lung interstitial macrophages was increased in COPD patients compared to non-COPD smokers (p = 0.018) and correlated with the severity of emphysematous lesions detected by CT scan (rs = 0.559, p < 0.001), whereas the amount of smoking showed no correlation with LILRB4 expression. Increased LILRB4 on interstitial macrophages was also observed in elastase-treated mice (p = 0.008). LILRB4-deficient mice showed severer emphysematous lesions with increased MMP-12 expression in the model. CONCLUSIONS: LILRB4 on interstitial macrophages was upregulated both in human COPD lungs and in a mouse model of emphysema. This upregulated LILRB4 may have a protective effect against emphysema formation, possibly through decreasing MMP-12 expression in the lungs.

PGC-1α regulates airway epithelial barrier dysfunction induced by house dust mite.

BACKGROUND: The airway epithelial barrier function is disrupted in the airways of asthmatic patients. Abnormal mitochondrial biogenesis is reportedly involved in the pathogenesis of asthma. However, the role of mitochondrial biogenesis in the airway barrier dysfunction has not been elucidated yet. This study aimed to clarify whether the peroxisome proliferator-activated receptor γ coactivator-1alpha (PGC-1α), a central regulator of mitochondrial biogenesis, is involved in the disruption of the airway barrier function induced by aeroallergens. METHODS: BEAS-2B cells were exposed to house dust mite (HDM) and the expressions of PGC-1α and E-cadherin, a junctional protein, were examined by immunoblotting. The effect of SRT1720, a PGC-1α activator, was investigated by immunoblotting, immunocytochemistry, and measuring the transepithelial electrical resistance (TEER) on the HDM-induced reduction in mitochondrial biogenesis markers and junctional proteins in airway bronchial epithelial cells. Furthermore,the effects of protease activated receptor 2 (PAR2) inhibitor, GB83, Toll-like receptor 4 (TLR4) inhibitor, lipopolysaccharide from Rhodobacter sphaeroides (LPS-RS), protease inhibitors including E64 and 4-(2-Aminoethyl) benzenesulfonyl fluoride hydrochloride (AEBSF) on the HDM-induced barrier dysfunction were investigated. RESULTS: The amounts of PGC-1α and E-cadherin in the HDM-treated cells were significantly decreased compared to the vehicle-treated cells. SRT1720 restored the expressions of PGC-1α and E-cadherin reduced by HDM in BEAS-2B cells. Treatment with SRT1720 also significantly ameliorated the HDM-induced reduction in TEER. In addition, GB83, LPS-RS, E64 and AEBSF prevented the HDM-induced reduction in the expression of PGC1α and E-cadherin. CONCLUSIONS: The current study demonstrated that HDM disrupted the airway barrier function through the PAR2/TLR4/PGC-1α-dependent pathway. The modulation of this pathway could be a new approach for the treatment of asthma.

Nitrosative stress in patients with asthma-chronic obstructive pulmonary disease overlap.

BACKGROUND: Asthma-chronic obstructive pulmonary disease overlap (ACO) has frequent exacerbations and a poor quality of life and prognosis compared with those of chronic obstructive pulmonary disease alone. However, the pathogenesis of ACO has not been fully elucidated yet. OBJECTIVES: The aim of this study was to investigate nitrosative stress, which causes a redox imbalance and tissue inflammation in the airways of patients with ACO, and to evaluate the relationship between nitrosative stress and the clinical course in study subjects. METHODS: Thirty healthy subjects and 56 asthmatic patients participated in this study. The asthmatic patients were divided into 33 asthmatic patients and 23 patients with ACO. The study subjects had been followed prospectively for 2 years to evaluate the clinical course. Nitrosative stress was evaluated based on the production of 3-nitrotyrosine (3-NT) in sputum cells. RESULTS: Production of 3-NT was significantly enhanced in patients with ACO compared with that in asthmatic patients. Amounts of reactive persulfides and polysulfides, newly identified powerful antioxidants, were significantly decreased in the ACO group. Baseline levels of 3-NT were significantly correlated with the frequency of exacerbations and decrease in FEV1 adjusted by age, smoking history, and blood eosinophil count. The 3-NT-positive cells were also significantly correlated with amounts of proinflammatory chemokines and cytokines. CONCLUSIONS: These findings suggested that greater nitrosative stress occurred in the airways of patients with ACO, and the degree of nitrosative stress was correlated with an impairment in the clinical course. Nitrosative stress might be related to the pathogenesis of ACO.

Correction to: Oxidative stress enhances the expression of IL-33 in human airway epithelial cells.

Figure 2 of this original publication was incorrectly formatted. The updated Fig. 2 is published in this correction article [1].

Oxidative stress enhances the expression of IL-33 in human airway epithelial cells.

BACKGROUND: Interleukin-33 (IL-33) is a cytokine belonging to the IL-1 family, and its possible involvement in the pathophysiology of COPD and viral-induced exacerbations has been demonstrated. IL-33 has been shown to be increased in the airway epithelial cells from COPD patients, but the regulating mechanism of IL-33 expression in airway epithelial cells remains largely unknown. In the current study, we examined whether oxidative stress, which participates in the pathogenesis of COPD, affects the expression of IL-33 in airway epithelial cells and also evaluated the effect during viral infection. METHODS: The involvement of oxidative stress in the expression of IL-33, and its signal pathway was examined after stimulation with hydrogen peroxide (H2O2), with or without stimulation by polyinosinic-polycytidylic acid [poly (I:C)], a synthetic analogue of dsRNA that mimics viral infection, or rhinovirus infection in NCI-H292 cells and primary human bronchial epithelial cells (HBECs). In addition, the effect of antioxidant, N-acetylcysteine (NAC) in the expression of IL-33 was compared between HBECs from healthy subjects and those from COPD patients. RESULTS: Treatment with H2O2 significantly potentiated IL-33 expression in NCI-H292 cells, and the potentiation was reversed by NAC treatment. Mitogen-activated protein kinase (MAPK) inhibitors, but not nuclear factor-kappa B inhibitors, also significantly decreased the H2O2-potentiated IL-33 expression. In addition, H2O2 significantly potentiated the poly (I:C)- or rhinovirus-stimulated IL-33 expression. In HBECs from healthy subjects, H2O2-potentiated IL-33 expression and its reversal by NAC was also confirmed. Under the condition without H2O2-stimulation, treatment with NAC significantly decreased the expression of IL-33 in HBECs from COPD patients, but not in those from healthy subjects. CONCLUSIONS: These results demonstrate that oxidative stress involves in the expression of IL-33 in airway epithelial cells via MAPK signal pathway and it augments IL-33 expression during viral infection. This mechanism may participate in the regulation of IL-33 expression in airway epithelial cells in COPD and the viral-induced exacerbations. Modulation of this pathway could become a therapeutic target for viral-induced exacerbations of COPD.

The first case of multiple pulmonary granulomas with amyloid deposition in a dental technician; a rare manifestation as an occupational lung disease.

BACKGROUND: Occupational lung diseases, such as pneumoconiosis, are one of the health problems of dental workers that have been receiving increasing interest. Pulmonary amyloidosis is a heterogenous group of diseases, and can be classified into primary (idiopathic) and secondary (associated with various inflammatory diseases, hereditary, or neoplastic). To date, the development of pulmonary amyloidosis in dental workers has not been reported. CASE PRESENTATION: A 58-year-old Japanese female presented with chest discomfort and low-grade fever that has persisted for 2 months. She was a dental technician but did not regularly wear a dust mask in the workplace. Chest X ray and computed tomography revealed multiple well-defined nodules in both lungs and fluorodeoxyglucose (FDG)-positron emission tomography revealed abnormal FDG uptake in the same lesions with a maximal standardized uptake value (SUV [max]) of 5.6. We next performed thoracoscopic partial resection of the lesions in the right upper and middle lobes. The histological examination of the specimens revealed granuloma formation with foreign body-type giant cells and amyloid deposition that was confirmed by Congo red staining and direct fast scarlet (DFS) staining that produce apple-green birefringence under crossed polarized light. Because there were no other causes underlying the pulmonary amyloidosis, we performed electron probe X-ray microanalysis (EPMA) of the specimens and the result showed silica deposition in the lesions. Based on these results, we finally diagnosed the patient with pulmonary granulomas with amyloid deposition caused by chronic silica exposure. Afterward, her symptoms were improved and the disease has not progressed for 2 years since proper measures against additional occupational exposure were implemented. CONCLUSIONS: Our case presented three important clinical insights: First, occupational exposure to silica in a dental workplace could be associated with the development of amyloid deposition in lung. Second, EPMA was useful to reveal the etiology of amyloid deposition in the lungs. Last, proper protection against silica is important to prevent further progression of the disease. In conclusion, our case suggested that occupational exposure to silica should be considered when amyloid deposition of unknown etiology is found in the lungs of working or retired adults.

Production of reactive persulfide species in chronic obstructive pulmonary disease.

BACKGROUND: Oxidative stress is a major aetiological factor driving chronic obstructive pulmonary disease (COPD). Recently recognised as potent antioxidants, reactive persulfide and polysulfide species are biosynthesised by cystathionine ß-synthase and cystathionine γ-lyase. The production of reactive persulfide and polysulfide species in the lungs of patients with COPD remain unknown. OBJECTIVES: The aim of this study was to examine the production of reactive persulfides and polysulfides, such as glutathione persulfide (GSSH), cysteine persulfide (CysSSH) and glutathione trisulfide (GSSSH), in lung-resident cells and epithelial lining fluid (ELF) obtained from patients with mild to moderate COPD. METHODS: Lung tissues, primary lung cells, ELF and sputum were obtained. The amounts of reactive persulfides and polysulfides in the cells and ELF were measured by liquid chromatography-tandem mass spectrometry with ß-(4-hydroxyphenyl) ethyl iodoacetamide as a trapping agent for hydroper/polysulfides. The amounts of synthases in the lung tissues, sputum and primary cells were quantified. RESULTS: The amounts of GSSH, CysSSH and GSSSH were decreased in the lung cells and ELF from patients with COPD. The amounts of reactive persulfides and polysulfides in the lung cells had a positive correlation with the degree of airflow limitation. By contrast, the amounts of the synthases were increased in the lung tissues and sputum cells of patients with COPD. CONCLUSIONS: We have identified a decrease in reactive persulfide and polysulfide species in the lungs of patients with COPD. These data suggest that the newly detected antioxidants reactive persulfides and polysulfides could be associated with the redox balance in the lungs of patients with COPD.

Decrease in an anti-ageing factor, growth differentiation factor 11, in chronic obstructive pulmonary disease.

RATIONALE: Cellular senescence is observed in the lungs of patients with COPD and may contribute to the disease pathogenesis. Growth differentiation factor 11 (GDF11) belongs to the transforming growth factor ß superfamily and was recently reported to be a circulating protein that may have rejuvenating effects in mice. We aimed to investigate the amounts of GDF11 in the plasma and the lungs of patients with COPD and elucidate the possible roles of GDF11 in cellular senescence. METHODS: The plasma levels of GDF11 were investigated in two separate cohorts by western blotting. The localisation and expression of GDF11 in the lungs were investigated by immunohistochemistry and quantitative reverse transcription PCR, respectively. The effects of GDF11 on both cigarette smoke extract (CSE)-induced cellular senescence in vitro and on elastase-induced cellular senescence in vivo were investigated. RESULTS: The levels of plasma GDF11 in the COPD group were decreased compared with the control groups in the two independent cohorts. The levels of plasma GDF11 were significantly positively correlated with pulmonary function data. The mRNA expression of GDF11 in mesenchymal cells from the COPD group was decreased. Chronic exposure to CSE decreased the production of GDF11. Treatment with GDF11 significantly inhibited CSE-induced cellular senescence and upregulation of inflammatory mediators, partly through Smad2/3 signalling in vitro. Daily GDF11 treatment attenuated cellular senescence and airspace enlargement in an elastase-induced mouse model of emphysema. CONCLUSIONS: The decrease in GDF11 may be involved in the cellular senescence observed in COPD.

27-Hydroxycholesterol accelerates cellular senescence in human lung resident cells.

Cellular senescence is reportedly involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). We previously showed that 27-hydroxycholesterol (27-OHC) is elevated in the airways of COPD patients compared with those in healthy subjects. The aim of this study was to investigate whether lung fibroblasts of COPD patients are senescent and to determine the effects of 27-OHC on senescence of lung resident cells, including fibroblasts and airway epithelial cells. Localization of senescence-associated proteins and sterol 27-hydroxylase was investigated in the lungs of COPD patients by immunohistochemical staining. To evaluate whether 27-OHC accelerates cellular senescence, lung resident cells were exposed to 27-OHC. Senescence markers and fibroblast-mediated tissue repair were investigated in the 27-OHC-treated cells. Expression of senescence-associated proteins was significantly enhanced in lung fibroblasts of COPD patients. Similarly, expression of sterol 27-hydroxylase was significantly upregulated in lung fibroblasts and alveolar macrophages in these patients. Treatment with the concentration of 27-OHC detected in COPD airways significantly augmented expression of senescence-associated proteins and senescence-associated ß-galactosidase activity, and delayed cell growth through the prostaglandin E2-reactive nitrogen species pathway. The 27-OHC-treated fibroblasts impaired tissue repair function. Fibroblasts from lungs of COPD patients showed accelerated senescence and were more susceptible to 27-OHC-induced cellular senescence compared with those of healthy subjects. In conclusion, 27-OHC accelerates cellular senescence in lung resident cells and may play a pivotal role in cellular senescence in COPD.

Possible role of Krüppel-like factor 5 in the remodeling of small airways and pulmonary vessels in chronic obstructive pulmonary disease.

BACKGROUND: Small airway remodeling is an important cause of the airflow limitation in chronic obstructive pulmonary disease (COPD). A large population of patients with COPD also have pulmonary hypertension. Krüppel-like factor 5 (KLF5) is a zinc-finger transcription factor that contributes to tissue remodeling in cardiovascular diseases. Here, we evaluate the possible involvement of KLF5 in the remodeling of small airways and pulmonary vessels in COPD. METHODS: Lung tissues were obtained from 23 control never-smokers, 17 control ex-smokers and 24 ex-smokers with COPD. The expression of KLF5 in the lung tissues was investigated by immunohistochemistry. We investigated whether oxidative/nitrosative stress, which is a major cause of the pathogenesis in COPD, could augment the production of KLF5. We examined the role of KLF5 in the stress-mediated tissue remodeling responses. We also investigated the susceptibility of KLF5 expression to nitrosative stress using bronchial fibroblasts isolated from the lung tissues. RESULTS: The expression of KLF5 was up-regulated in the small airways and pulmonary vessels of the COPD patients and it was mainly expressed in bronchial fibroblasts and cells of the pulmonary vessels. The extent of the KLF5 expression in the small airway of the COPD group had a significant correlation with the severity of the airflow limitation. Oxidative/nitrosative stress augmented the production of KLF5 in lung fibroblasts as well as the translocation of KLF5 into the nuclei. Silencing of KLF5 suppressed the stress-augmented differentiation into myofibroblasts, the release of collagens and metalloproteinases. Bronchial fibroblasts from the patients with COPD highly expressed KLF5 compared to those from the control subjects under basal condition and were more susceptible to the induction of KLF5 expression by nitrosative stress compared to those from the control subjects. CONCLUSION: We provide the first evidence that the expression of KLF5 is up-regulated in small airways and pulmonary vessels of patients with COPD and may be involved in the tissue remodeling of COPD.

Extracellular ATP is involved in dsRNA-induced MUC5AC production via P2Y2R in human airway epithelium.

BACKGROUND: In response to tissue damage or inflammation, adenosine-5'-triphosphate (ATP) is released into the extracellular compartment and has been demonstrated to augment inflammation via purinergic P2 receptors (P2Rs). Recently, ATP has been shown to be increased in the airways of COPD patients. In the present study, we examined the possible involvement of extracellular ATP in airway mucus hypersecretion during viral-induced COPD exacerbations. METHODS: The involvement of extracellular ATP in the release of a major airway mucin, MUC5AC, and its signal pathway was examined after stimulation with polyinosine-polycytidylic acid [poly(I:C)], a synthetic analog of dsRNA to mimic viral infection, and rhinovirus (RV) infection in NCI-H292 cells and differentiated airway epithelial cells from COPD patients. RESULTS: Treatment with poly(I:C) significantly increased the amount of extracellular ATP and induced MUC5AC release in NCI-H292 cells. Pre-treatment with a pannexin channel inhibitor, carbenoxolone (CBX), reduced the amount of extracellular ATP and suppressed MUC5AC release from poly(I:C)-treated cells. Pre-treatment with the P2R antagonist suramin significantly reduced the expression and release of MUC5AC. The inhibitory effects of CBX and suramin on the release of ATP and/or MUC5AC were replicated with RV infection. Pre-treatment with suramin also significantly reduced the expression and amount of extracellular EGFR ligands and the phosphorylation of EGFR and ERK in poly(I:C)-treated cells. In addition, pre-treatment with a P2Y2 receptor siRNA significantly suppressed the poly(I:C)-potentiated EGFR ligands and MUC5AC release. After poly(I:C) stimulation, the expression of MUC5AC in the differentiated cells from COPD patients was significantly higher than those from healthy subjects and the values of MUC5AC expression were inversely related with forced expiratory volume in 1 s (FEV1) % predicted. The inhibitory effects of CBX and suramin on poly(I:C)-potentiated MUC5AC expression were confirmed in differentiated airway epithelium from COPD patients. CONCLUSIONS: These results demonstrate that dsRNA induces the release of ATP via pannexin channel and that the extracellular ATP is involved in the expression and release of MUC5AC, mainly via P2Y2R, in an autocrine manner. Modulation of this pathway could be a therapeutic target for viral-induced mucus hypersecretion in COPD exacerbations.

Simultaneous development of sarcoidosis and cutaneous vasculitis in a patient with refractory Crohn's disease during infliximab therapy.

BACKGROUND: Paradoxical inflammations during anti-TNF-α therapy are defined as adverse effects such as psoriasiform skin lesions, uveitis and sarcoidosis-like granulomas induced by immune reactions, not by infectious agents. Here, we report a very rare case of the simultaneous development of sarcoidosis and cutaneous vasculitis in a patient with refractory Crohn's disease during infliximab therapy and both of which resolved spontaneously without the cessation of infliximab. CASE PRESENTATION: In September 2000, 23-year old Japanese male was diagnosed with Crohn's disease. Prednisolone in combination with mesalazine was introduced at first and succeeded for almost one year. In June 2002, since his gastrointestinal symptoms relapsed and were refractory, infliximab (IFX) therapy 5 mg/kg was introduced. In February 2011, because he had repeated arthralgia almost every intravenous IFX administration, IFX was increased to 10 mg/kg under the diagnosis of a secondary failure of IFX. In December 2012, he complained of slight dry cough and an itchy eruption on both lower limbs, and he was referred to our hospital due to the appearance of bilateral hilar lymphadenopathy on chest X-ray examination. Chest computed tomogram revealed bilateral hilar lymphadenopathy and fine reticulonodular shadows on the bilateral upper lungs. Serum calcium, angiotensin-converting enzyme and soluble interleukin 2 receptor levels were not elevated, but the titer of antinuclear antibody was considerably elevated. Mycobacterium infection was carefully excluded. Trans-bronchial lung biopsy showed non-caseating epithelioid cell granulomas compatible with sarcoidosis. The skin biopsy of the right limb was diagnosed as leukocytoclastic vasculitis. The patient was diagnosed as having a series of paradoxical inflammations during anti-TNF-α therapy. Since his paradoxical inflammations were not severe and opportunistic infections were excluded, IFX was cautiously continued for refractory Crohn's disease. Nine months later, not only his intrathoracic lesions but also his cutaneous lesions had spontaneously resolved. CONCLUSION: Physicians caring for patients with anti-TNF-α therapy should know that, based on a careful exclusion of infectious agents and thoughtful assessment of the patient's possible risks and benefits, paradoxical inflammations can be resolved without the cessation of anti-TNF-α therapy.

An indocyanine green fluorescence-guided operation for diagnosing and treating pleuroperitoneal communication.

Pleuroperitoneal communication occurs when ascites moves from the abdominal cavity to the pleural cavity via a diaphragmatic fistula. Managing large pleural fluid volumes is challenging, often requiring an operation. Identifying small diaphragmatic fistulas during the operation can be problematic, but ensuring their detection improves outcomes. This video tutorial presents a recent empirical case in which we successfully identified and closed a pleuroperitoneal contact using a thoracoscopic surgical procedure aided by indocyanine green fluorescence imaging. The patient, a 66-year-old woman, was hospitalized due to acute dyspnoea from a right thoracic pleural effusion during hepatic ascites treatment for cirrhosis. Because ascites decreased with pleural fluid drainage, surgical intervention was considered due to suspicion of a pleuroperitoneal connection. During the operation, indocyanine green was injected intraperitoneally, and near-infrared fluorescence-guided thoracoscopy pinpointed the location of the diaphragmatic fistula. The fistula was sutured and reinforced with a polyglycolic acid sheet and fibrin glue. Detecting the fistula intraoperatively is crucial to prevent recurrence, and the indocyanine green fluorescence method is a safe and effective technique for detecting small fistulas.

Hermansky-Pudlak Syndrome with an Improvement in the Respiratory Symptoms after the Administration of Pirfenidone: A Case Report.

Herein, we report a case of Hermansky-Pudlak syndrome (HPS) in which respiratory symptoms improved with pirfenidone treatment. A 43-year-old Japanese woman with oculocutaneous albinism presented with a cough and dyspnea. High-resolution computed tomography revealed areas of reticular and frosted lung opacities. The diagnosis of HPS was confirmed by a prolonged bleeding time and HPS1 gene mutation. Generally, there is no effective treatment for interstitial pneumonia associated with HPS except for lung transplantation. In the present case, the cough and dyspnea improved with pirfenidone administration. Therefore, clinicians should administer pirfenidone in challenging transplantation cases and during the waiting period for transplantation.

Associations between birth weight and lung function in a Japanese adult population: The tohoku medical megabank community-based cohort study.

BACKGROUND: Birth weight, as a measure of intrauterine growth, is commonly used in epidemiological studies and is reported to be associated with adult lung function. However, findings regarding this association in previous studies have been inconsistent. Furthermore, no studies have reported associations stratified by age or smoking status, or adjusted for eosinophil count or other parameters related to type 2 airway inflammation. METHODS: This cross-sectional study included 2632 men and 7237 women aged ≥20 years living in Miyagi Prefecture, Japan. Lung function was assessed based on spirometry. Birth weight data were obtained through a questionnaire survey. Analysis of covariance was used to evaluate the associations between birth weight and lung function, adjusting for potential confounders. Stratified analyses by age and smoking status were also conducted, together with a sub-analysis for low birth-weight participants. RESULTS: Birth weight was positively associated with forced expiratory volume in 1 s (FEV1) for both sexes and with vital capacity in women, after adjusting for height, age, smoking status, and parameters related to type 2 airway inflammation. The stratified analysis for smoking status revealed associations in never-smokers and ex-smokers. When stratified by age, the associations were confirmed in middle-aged participants. The effect of smoking status on the FEV1 of low birth-weight participants was not significant. CONCLUSIONS: Our analysis of a large, Japanese adult population showed that birth weight was independently and positively associated with adult lung function, even after adjustment for age, height, smoking status, and parameters related to type 2 airway inflammation.