Lysophospholipid Acyltransferase 9 Promotes Emphysema Formation via Platelet-activating Factor.

Cigarette smoking is known to be the leading cause of chronic obstructive pulmonary disease (COPD). However, the detailed mechanisms have not been elucidated. PAF (platelet-activating factor), a potent inflammatory mediator, is involved in the pathogenesis of various respiratory diseases such as bronchial asthma and COPD. We focused on LPLAT9 (lysophospholipid acyltransferase 9), a biosynthetic enzyme of PAF, in the pathogenesis of COPD. LPLAT9 gene expression was observed in excised COPD lungs and single-cell RNA sequencing data of alveolar macrophages (AMs). LPLAT9 was predominant and upregulated in AMs, particularly monocyte-derived AMs, in patients with COPD. To identify the function of LPLAT9/PAF in AMs in the pathogenesis of COPD, we exposed systemic LPLAT9-knockout (LPALT9-/-) mice to cigarette smoke (CS). CS increased the number of AMs, especially the monocyte-derived fraction, which secreted MMP12 (matrix metalloprotease 12). Also, CS augmented LPLAT9 phosphorylation/activation on macrophages and, subsequently, PAF synthesis in the lung. The LPLAT9-/- mouse lung showed reduced PAF production after CS exposure. Intratracheal PAF administration accumulated AMs by increasing MCP1 (monocyte chemoattractant protein-1). After CS exposure, AM accumulation and subsequent pulmonary emphysema, a primary pathologic change of COPD, were reduced in LPALT9-/- mice compared with LPLAT9+/+ mice. Notably, these phenotypes were again worsened by LPLAT9+/+ bone marrow transplantation in LPALT9-/- mice. Thus, CS-induced LPLAT9 activation in monocyte-derived AMs aggravated pulmonary emphysema via PAF-induced further accumulation of AMs. These results suggest that PAF synthesized by LPLAT9 has an important role in the pathogenesis of COPD.

Rapidly progressive mucus plugs in allergic bronchopulmonary mycosis.

INTRODUCTION: Allergic bronchopulmonary mycosis (ABPM) is a chronic airway disease characterized by the presence of fungi that trigger allergic reactions and airway obstruction. Here, we present a unique case of ABPM in which a patient experienced sudden respiratory failure due to mucus plug-induced airway obstruction. The patient's life was saved by venovenous extracorporeal membrane oxygenation (VV-ECMO) and bronchoscopic removal of the plug. This case emphasizes the clinical significance of mucus plug-induced airway obstruction in the differential diagnosis of respiratory failure in patients with ABPM. CASE STUDY: A 52-year-old female clerical worker with no smoking history, presented with dyspnea. CT scan revealed mucus plugs in both lungs. Despite treatment, the dyspnea progressed rapidly to respiratory failure, leading to VV-ECMO placement. RESULTS: CT revealed bronchial wall thickening, obstruction, and extensive atelectasis. Bronchoscopy revealed extensive mucus plugs that were successfully removed within two days. The patient's respiratory status significantly improved. Follow-up CT revealed no recurrence. Fungal cultures identified Schizophyllum commune, confirming ABPM. Histological examination of the mucus plugs revealed aggregated eosinophils, eosinophil granules, and Charcot-Leyden crystals. Galectin-10 and major basic protein (MBP) staining supported these findings. Eosinophil extracellular traps (EETs) and eosinophil cell death (ETosis), which contribute to mucus plug formation, were identified by citrullinated histone H3 staining. CONCLUSION: Differentiating between asthma exacerbation and mucus plug-induced airway obstruction in patients with ABPM and those with acute respiratory failure is challenging. Prompt evaluation of mucous plugs and atelectasis using CT and timely decision to introduce ECMO and bronchoscopic mucous plug removal are required.

Role of CC Chemokine Ligand 17 in Mouse Models of Chronic Obstructive Pulmonary Disease.

Lung function deterioration is significantly associated with poor prognosis in patients with chronic obstructive pulmonary disease (COPD). We previously reported that CC chemokine ligand 17/thymus and activation-regulated chemokine (CCL17/TARC) could be a predictive factor of lung function decline in patients with COPD. However, the role of CCL17 in the pathogenesis of COPD is unclear. Here we examined the role of CCL17 in lung inflammation using mouse COPD models. Exposure to cigarette smoking induced CCL17 production in bronchial epithelial cells and accumulation of alveolar macrophages in the lungs. Intranasal administration of recombinant CCL17 further enhanced cigarette smoke-induced macrophage accumulation and also aggravated elastase-induced pulmonary emphysema. We confirmed that cigarette smoke (CS) extract as well as hydrogen peroxide upregulated CCL17 in BAES-2B cells. Of note, macrophages of both M1 and M2 surface markers were accumulated by cigarette smoke. Both alveolar macrophage accumulation via exposure to cigarette smoking and emphysematous changes induced by elastase administration were significantly reduced in CCL17-deficient mice. We further demonstrated that CCL17 strongly induced the expression of CC chemokine ligand 2 (CCL2), a chemoattractant for macrophages, in RAW264.7 cells, and its production was inhibited by knockdown of CCR4, the receptor of CCL17. Collectively, the present results demonstrate that CCL17 is produced by lung epithelial cells upon CS exposure. Furthermore, CCL17 is involved in CS-induced accumulation of alveolar macrophages and development of elastase-induced pulmonary emphysema, possibly through CCL17-induced production of CCL2 by macrophages. Our findings may provide a new insight into the pathogenesis of COPD.

Thymus and activation-regulated chemokine (TARC/CCL17) predicts decline of pulmonary function in patients with chronic obstructive pulmonary disease.

BACKGROUND: The deterioration of pulmonary function, such as FEV1-decline, is strongly associated with poor prognosis in patients with chronic obstructive pulmonary disease (COPD). However, few investigations shed light on useful biomarkers for predicting the decline of pulmonary function. We evaluated whether thymus and activation-regulated chemokine (TARC), a Th2 inflammation marker, could predict rapid FEV1-decline in COPD patients. METHODS: We recruited 161 patients with stable COPD and performed pulmonary function test once every six months. At the time of registration, blood tests, including serum levels of TARC were performed. We assessed the correlation between changes in parameters of pulmonary function tests and serum levels of TARC. The rapid-decline in pulmonary function was determined using 25th percentile of change in FEV1 or FEV1 percent predicted (%FEV1) per year. RESULTS: In the FEV1-rapid-decline group, the frequency of exacerbations, the degree of emphysema, and serum levels of TARC was higher than in the non-rapid-decline group. When using %FEV1 as a classifier instead of FEV1, age, the frequency of exacerbations, the degree of emphysema and serum levels of TARC in the rapid-decline group was significantly greater than those in the non-rapid-decline group. In univariate logistic regression analysis, TARC was the significant predictive factor for rapid-decline group. In multivariate analysis adjusted for emphysema, serum levels of TARC are independently significant predicting factors for the rapid-decline group. CONCLUSIONS: TARC is an independent predictive biomarker for the rapid-decline in FEV1. Measuring serum TARC levels may help the management of COPD patients by predicting the risk of FEV1 decline.

Effect of Iron Deficiency on a Murine Model of Smoke-induced Emphysema.

Smoking is a major risk factor for chronic obstructive pulmonary disease (COPD). Smoking susceptibility is important for the onset and development of COPD. We previously reported an association between serum iron concentrations and pulmonary function in male smokers. However, the mechanism governing smoking susceptibility in relation to iron deficiency is unclear; this study aimed to elucidate this mechanism. C57BL/6 male mice were fed an iron-deficient or normal diet and then exposed to cigarette smoke. BAL, histological analysis, and pulmonary function tests were performed after cigarette smoke exposure. Human alveolar type II epithelial A549 cells were treated with an iron chelator. Subsequently, A549 cells were exposed to cigarette smoke extract. In mice exposed to cigarette smoke for 2 weeks, the concentration of alveolar macrophages in the BAL fluid recovered from iron-deficient mice was significantly higher than that in normal diet mice. IL-6 and MCP-1 (monocyte chemotactic protein 1) concentrations in the BAL fluid increased significantly from baseline in iron-deficient mice, but not in normal diet mice. In mice exposed to cigarette smoke for 8 weeks, the pathological mean linear intercepts, physiological total lung capacity, and functional residual capacity in the lungs of iron-deficient mice were significantly greater than in normal diet mice. Phosphorylation of NF-κB was enhanced in the lungs of iron-deficient mice exposed to cigarette smoke and in the iron-chelating A549 cells exposed to cigarette smoke extract. Iron deficiency exaggerated cigarette smoke-induced pulmonary inflammation, suggesting that it may accelerate COPD development.

Phase II Study of Low-Dose Afatinib Maintenance Treatment Among Patients with EGFR-Mutated Non-Small Cell Lung Cancer: North Japan Lung Cancer Study Group Trial 1601 (NJLCG1601).

LESSONS LEARNED: Low-dose afatinib maintenance treatment among patients with EGFR-mutated NSCLC achieved long-time to treatment failure with fewer treatment-related AEs without detracting from the therapeutic efficacy. This modified regimen represents a practical usage that balances effectiveness and safety. BACKGROUND: Although afatinib is an effective therapy for patients with EGFR-mutated non-small cell lung cancer (NSCLC), drug-related adverse events (AEs) have often necessitated dose reductions. In a post hoc analysis of the LUX-Lung 3 and 6 trials, there was no difference in median progression-free survival (PFS) between patients who had the dose of afatinib reduced and those who did not. We thus evaluated the efficacy and tolerability of low-dose afatinib maintenance treatment among patients with NSCLC harboring EGFR mutations who had not been previously treated. METHODS: Eligible patients received afatinib 40 mg orally once daily. When prescribed grade ≥ 2 AEs, rash of grade ≥ 3, or unacceptable toxicity occurred, the afatinib dose was reduced from 40 to 30 mg and if needed from 30 to 20 mg. The primary endpoint was the 1-year PFS rate. Secondary endpoints were PFS, overall response rate (ORR), and toxicity. RESULTS: Among 30 patients, 93% had adenocarcinoma, 53% had exon 19 deletion, 37% had L858R, and 10% had minor mutations. The 1-year PFS rate was 50% (95% confidence interval [CI], 31.3-66.1) and the median PFS was 11.8 months (95% CI, 7.1-21.4). The incidence rate of grade ≥ 3 toxicities was 57%, including elevated aspartate aminotransferase/alanine aminotransferase level (13%), diarrhea (10%), and paronychia (10%). CONCLUSION: Low-dose afatinib maintenance treatment reduced treatment-related AEs without detracting from the therapeutic efficacy.

MafB enhances the phagocytic activity of RAW264.7 macrophages by promoting Fcgr3 expression.

This study was designed to investigate whether MafB influences the phagocytic activity of macrophages by modulating the expression of the Fc receptors for IgG (FcγRs), Fcgr2b and Fcgr3. In macrophages, FcγRs are critical for the phagocytosis of opsonized pathogens. Of these receptors, Fcgr3 has been shown to play an important role in host defense. As a model to evaluate the mechanism by which MafB influences phagocytosis, we utilized a macrophage cell-line that constitutively expresses a MafB-specific short hairpin (sh)RNA (RAW264.7-MafB-shRNA). Specifically, the levels of Fc receptor mediated-phagocytosis and the levels of FcγRs surface expression were evaluated by flow cytometry analysis, while quantitative real-time PCR analysis was utilized to examine the mRNA expression levels of FcγRs. Compared to the control cell population, RAW264.7-MafB-shRNA cells exhibited significant reductions in Fcgr3 expression and Fc receptor-mediated phagocytosis, but no difference in Fcgr2b expression. Likewise, there was markedly decreased surface expression of Fcgr3 antigen, but not Fcgr2b antigen, in RAW264.7-MafB-shRNA, compared to the control cells. Meanwhile, the observed reduction in the phagocytic activity of the MafB-shRNA-expressing cells was attenuated by ectopic expression of Fcgr3. Together, the results presented here indicate that MafB influences the phagocytic activity of macrophages by promoting Fcgr3, but not Fcgr2b, expression.

Association between plasma adiponectin levels and decline in forced expiratory volume in 1 s in a general Japanese population: the Takahata study.

BACKGROUND: Adiponectin is an anti-inflammatory and cardio-protective cytokine. However, several studies have demonstrated that plasma adiponectin levels were inversely associated with pulmonary function in patients with chronic obstructive pulmonary disease, suggesting a proinflammatory or pulmonary-destructive role. It is still unclear whether adiponectin is a potent biomarker predicting declines in pulmonary function. The aim of this study was to investigate the association between adiponectin and pulmonary function among Japanese individuals who participated in an annual health check-up. METHODS: Spirometry and blood sampling, including measurements of plasma adiponectin, were performed for 3,253 subjects aged 40 years or older who participated in a community-based annual health check-up in Takahata, Japan from 2004 to 2006. In 2011, spirometry was re-performed, and the data from 872 subjects (405 men and 467 women) were available for a longitudinal analysis. RESULTS: Plasma adiponectin levels were found to be significantly associated with age, body mass index (BMI), and alanine aminotransferase (ALT), triglycerides (TG), and high-density lipoprotein-cholesterol (HDL-c) levels among both men and women in the study population. Plasma adiponectin levels were found to be associated with lifetime cigarette consumption (Brinkman index, BI) in men only. Plasma adiponectin levels were inversely correlated with forced expiratory volume in 1 s (FEV1) per forced vital capacity in both men and women. In addition, the annual change in FEV1 was inversely associated with plasma adiponectin levels in both genders. A multiple linear regression analysis revealed that this association was independent of other confounding factors such as age, BMI, BI, ALT, TG, and HDL-c. CONCLUSIONS: The results of the present study suggest that adiponectin levels are predictive of declines in FEV1 in the general population.

Antibiotic treatment for patients with exacerbation of chronic obstructive pulmonary disease: A systematic review and meta-analysis.

BACKGROUND: Although respiratory tract infection is a significant factor that triggers exacerbation of chronic obstructive pulmonary disease (COPD), the benefit of antibiotics for patients with COPD exacerbation remains controversial. It is necessary to evaluate the efficacy and safety of antibiotics versus placebo in such patients. METHODS: We conducted a systematic review and meta-analysis of randomized controlled trials of antibiotics versus placebo for the treatment of COPD exacerbation, and compared the frequencies of treatment failure, mortality, and adverse events between patients treated with antibiotics and those treated with placebo. RESULTS: A total of six studies were included in this meta-analysis. The frequency of treatment failure was significantly lower in the antibiotic-treated patients compared to the placebo-treated patients (odds ratios [OR] 0.50, 95% confidence intervals [CI] 0.35-0.71, p = 0.0001). There was no significant difference between the two groups in mortality (OR 0.44, 95% CI 0.05-3.76, p = 0.45) or frequency of adverse events (OR 1.05, 95% CI 0.75-1.48, p = 0.78). CONCLUSION: In the current systematic review and meta-analysis, we found that antibiotics were superior to placebo in patients with exacerbated COPD, as shown by the lower treatment failure rate.

Participant Selection from the General Japanese Population for Pulmonary Function Tests Using a Questionnaire on Symptoms and Smoking Habits during Annual Health Checkups: The Yamagata-Takahata Study.

Objective Pulmonary function tests are essential for diagnosing respiratory diseases, such as chronic obstructive pulmonary disease (COPD), but are typically not performed in Japan during annual health checkups, which hinders the early diagnosis of respiratory diseases. Methods Individuals who agreed to participate in the Yamagata-Takahata study during medical checkups in Takahata (Yamagata Prefecture, Japan) in 2011 were examined. We interviewed 669 participants (49.0% men; mean age, 67.7 years old) regarding their respiratory symptoms and smoking habits and performed pulmonary function tests during the study. Results Based on pulmonary function test results, 141 participants had pulmonary dysfunction, and 115 had obstructive pulmonary dysfunction. The risk of respiratory dysfunction, particularly obstructive respiratory dysfunction, was examined by referring to a questionnaire tool for an early COPD diagnosis. The associations between age, the smoking history, respiratory symptoms, and obstructive respiratory dysfunction were evaluated. Obstructive respiratory dysfunction was found in 17.6% of participants ≥50 years old and 19.5% ≥60 years old, 30.3% had a smoking history, and 32.8% had respiratory symptoms. Furthermore, the participants with multiple factors had a higher probability of obstructive respiratory dysfunction. Conclusion Subjects with obstructive pulmonary dysfunction are expected to be efficiently identified by extracting individuals by age and smoking habit and through a respiratory symptom questionnaire, although pulmonary function tests cannot be performed for all individuals during health checkups.

Hyperhomocysteinaemia predicts the decline in pulmonary function in healthy male smokers.

Hyperhomocysteinaemia is associated with chronic obstructive pulmonary disease. However, the relationship between plasma homocysteine levels and spirometric measures has not been investigated in a general population. We aimed to determine whether homocysteine levels are predictive for a rapid decline in lung function among healthy current smokers. Blood sampling and spirometry were performed on subjects participating in a community-based annual health check in Takahata, Japan, from 2004 to 2006 (n=3257). Spirometry was re-evaluated in 147 male current smokers in 2009. On initial assessment, forced vital capacity (FVC) % predicted and forced expiratory volume in 1 s (FEV1) % predicted correlated inversely with homocysteine levels and were predictive for homocysteine levels, independent of various clinical factors. Homocysteine levels were higher in subjects with restrictive, obstructive or mixed ventilatory disorders. In addition, homocysteine levels were higher in subjects with mixed ventilatory disorders, compared with restrictive or obstructive disorders. On follow-up, subjects showing a decline in FEV1 had higher homocysteine levels than those who did not. Logistic regression analysis indicated that homocysteine levels were predictive for a decline in FEV1. FVC % pred and FEV1 % pred were significantly associated with homocysteine levels, and hyperhomocysteinaemia predicted the annual rate of decline in FEV1 among male smokers.

Retrospective analysis of the relationship between decline in FEV(1) and abdominal circumference in male smokers: the Takahata study.

BACKGROUND: Metabolic syndrome (Mets) is reportedly associated with chronic obstructive pulmonary disease (COPD). However, the relationship between abdominal circumference (AC) and decline in FEV(1) has not been elucidated. We aimed to investigate this relationship among male current smokers. METHODS: Spirometry was performed on subjects (n = 3,257) ≥ 40 years of age, who participated in a community-based annual health check in Takahata, Japan, from 2004 through 2006 (visit 1). Spirometry was re-evaluated, and AC was assessed in 147 of the male current smokers in 2009 (visit 2). The diagnosis of Mets was based on the criteria used in the Hisayama Study. RESULTS: No significant relationships were observed between AC and spirometric parameters such as % predicted forced vital capacity (FVC), % predicted forced expiratory volume in 1 s (FEV(1)) and FEV(1)/FVC. However, decline in FEV(1) was significantly correlated with AC. Multivariate logistic regression analysis showed that AC was a significant discriminating factor for decline in FEV(1), independently of age, Brinkman index and change in body mass index from visit 1 to visit 2. At visit 2, there was a greater prevalence of decline in FEV(1) among subjects with Mets (n=17) than among those without Mets. Although there were no differences in % predicted FVC, % predicted FEV(1) or FEV(1)/FVC between subjects with or without Mets, the rate of decline in FEV(1) was significantly greater in subjects with Mets than in those without. CONCLUSIONS: This retrospective analysis suggested that measuring AC may be useful for discriminating male smokers who show a decline in FEV(1).

Relationship between plasma fibrinogen levels and pulmonary function in the japanese population: the Takahata study.

BACKGROUND: Plasma fibrinogen is considered a biomarker of respiratory disease, owing to the relationship between plasma fibrinogen and pulmonary function established in Western populations. However, such a relationship has not yet been confirmed in an Asian population. We assessed this relationship in the general Japanese population. METHODS: Totally, 3,257 men and women aged ≥40 years who participated in a community-based annual health checkup in Takahata, Japan, from 2004 to 2006, underwent spirometry, and their plasma fibrinogen levels were determined. RESULTS: We found an inverse relationship between spirometric measures (percent predicted forced vital capacity [%FVC] and forced expiratory volume in 1s [%FEV1], and FEV1/FVC) and plasma fibrinogen levels in men, but not in women. The plasma fibrinogen levels were significantly higher in subjects with restrictive, obstructive, and mixed ventilatory disorders than in those with normal spirometry results. Multiple linear regression analysis revealed that in men, plasma fibrinogen levels were predictive for %FVC and %FEV1 (independent of age, body mass index, and cigarette smoking) but not for FEV1/FVC. CONCLUSIONS: Plasma fibrinogen was significantly associated with pulmonary function in Japanese men, and as such, plasma fibrinogen might be a potent biomarker for pulmonary dysfunction in men.

Secretoglobin 3A2 protects lung from developing cigarette smoke-induced pulmonary emphysema.

Secretoglobin (SCGB) 3A2 is a bioactive molecule exhibiting various functions such as improving allergic airway inflammation and pulmonary fibrosis and promoting bronchial branching and proliferation during lung development. To determine if and how SCGB3A2 is involved in chronic obstructive pulmonary disease (COPD), a multifactorial disease with both airway and emphysematous lesions, a COPD mouse model was created by exposing Scgb3a2-deficient (KO), Scgb3a2-lung-specific overexpressing (TG), and wild type (WT) mice to cigarette smoke (CS) for 6 months. The KO mice showed loss of lung structure under control condition, and CS exposure resulted in more expansion of airspace and destruction of alveolar wall than WT mouse lungs. In contrast, TG mouse lungs showed no significant changes after CS exposure. SCGB3A2 increased the expression and phosphorylation of signal transducers and activators of transcription (STAT)1 and STAT3, and the expression of α1-antitrypsin (A1AT) in mouse lung fibroblast-derived MLg cells and mouse lung epithelial-derived MLE-15 cells. In MLg cells, A1AT expression was decreased in Stat3-knockdown cells, and increased upon Stat3 overexpression. STAT3 formed a homodimer when cells were stimulated with SCGB3A2. Chromatin immunoprecipitation and reporter assays demonstrated that STAT3 binds to specific binding sites on the Serpina1a gene encoding A1AT and upregulates its transcription in lung tissues of mice. Furthermore, nuclear localization of phosphorylated STAT3 upon SCGB3A2 stimulation was detected by immunocytochemistry. These findings demonstrate that SCGB3A2 protects the lungs from the development of CS-induced emphysema by regulating A1AT expression through STAT3 signaling.

The effect of lifestyle on the mortality associated with respiratory diseases in the general population.

Lifestyle factors, including smoking habit, diet, and physical activity, affect the prognosis of various diseases. We elucidated the effect of lifestyle factors and health status on deaths from respiratory diseases in the general Japanese population using data from a community health examination database. Data of the nationwide screening program of the Specific Health Check-up and Guidance System (Tokutei-Kenshin), targeting the general population in Japan, from 2008 to 2010 were analyzed. The underlying causes of death were coded according to the International Classification of Diseases (ICD)-10. The hazard ratios of the incidence of mortality associated with respiratory disease were estimated using the Cox regression model. This study included 664,926 participants aged 40-74 years, who were followed up for 7 years. There were 8051 deaths, including 1263 (15.69%) deaths from respiratory diseases. The independent risk factors of mortality associated with respiratory diseases were male sex, older age, low body mass index, no exercise habit, slow walking speed, no drinking habit, smoking history, history of cerebrovascular diseases, high hemoglobin A1c and uric acid levels, low low-density lipoprotein cholesterol level, and proteinuria. Aging and decline of physical activity are significant risk factors for mortality associated with respiratory diseases, regardless of the smoking status.

Oxidized phospholipid, 1-palmitoyl-2-(9'-oxo-nonanoyl)-glycerophosphocholine (PON-GPC), produced in the lung due to cigarette smoking, impairs immune function in macrophages.

INTRODUCTION: Pulmonary innate immunity is impaired in cigarette smokers, because the abundant oxidants present in cigarette smoke (CS) cause injury to lung cells. Pulmonary surfactant is a unique material that is important roles in reducing surface tension in the lung and defending against invading pathogens. Oxidants reportedly cleave surfactant phospholipids, resulting in the production of oxidized phospholipids, such as 1-palmitoyl-2-(9'-oxo-nonanoyl)-glycerophosphocholine (PON-GPC). Although oxidation of surfactant lipids is thought to be involved in the pathogenesis of smoking-related lung disease, there are no reports on the effect of oxidized surfactant lipid on the immune function of macrophages. We hypothesized that cigarette smoking elevates PON-GPC levels in the lung, and that PON-GPC impairs the innate immune function of macrophages. METHODS: The levels of PON-GPC in bronchoalveolar lavage fluid (BALF) recovered from mice exposed to CS for 2 weeks (n = 7) were measured by liquid chromatography with electrospray-ionization tandem mass spectrometry. The effects of PON-GPC on inducibility of tumor necrosis factor (TNF)-α, nitric oxide (NO), and nicotinamide adenine dinucleotide phosphate (NADP(+)) production, as well as bactericidal activity, were investigated in RAW264.7 cells or primary alveolar macrophages. RESULTS: The levels of PON-GPC in BALF of mice exposed to CS were significantly elevated, compared with those of control mice. PON-GPC attenuated TNF-α, NO, and NADP(+) production in macrophages on stimulation with LPS plus IFN-γ. PON-GPC treatment attenuated the phosphorylation of p38 mitogen-activated protein kinase (MAPK). In addition, PON-GPC reduced the bactericidal activity of RAW264.7 cells. CONCLUSIONS: CS may attenuate innate immunity in the lungs through oxidization of surfactant phospholipids.

Treatment efficacy of LAMA versus placebo for stable chronic obstructive pulmonary disease: A systematic review and meta-analysis.

BACKGROUND: Four long-acting muscarinic antagonists (LAMAs), tiotropium, glycopyrronium, aclidinium, and umeclidinium, are currently available for the treatment of stable chronic obstructive pulmonary disease (COPD). However, no integrated analysis has sought to determine the effectiveness of these LAMAs. Thus, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety of LAMA versus placebo in patients with stable COPD. METHODS: A literature search of relevant randomized control trials that administered LAMA to stable COPD patients was conducted, and the exacerbations, quality of life (QoL), dyspnea score, lung function, and adverse event of patients were evaluated. RESULTS: A total of 33 studies were included in this meta-analysis. LAMA significantly decreased the frequency of exacerbations compared to the placebo (OR 0.75; 95% CI 0.66 to 0.85; P < 0.001). The mean changes in the St George's Respiratory Questionnaire score (mean difference, -3.61; 95% CI, -4.27 to -2.95; P < 0.00001), transitional dyspnea index score (mean difference 1.00; 95% CI 0.83 to 1.17; P < 0.00001), and trough FEV1 (mean difference 0.12; 95% CI 0.11 to 0.13; P < 0.0001) indicated significantly greater improvement in the LAMA group than the placebo group. The number of withdrawals due to adverse events in the LAMA group was significantly fewer than that in the placebo group (OR -0.02; 95% CI -0.03 to -0.01; P = 0.002). CONCLUSION: LAMA is superior to placebo due to lower frequency of exacerbations and adverse events, as well as higher trough FEV1, QoL, and dyspnea score for stable COPD.

Adverse reactions to BNT162b2 mRNA COVID-19 vaccine in medical staff with a history of allergy.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) vaccination is progressing globally. Several adverse reactions have been reported with vaccination against COVID-19. It is unknown whether adverse reactions to COVID-19 vaccination are severe in individuals with allergies. METHODS: We administered the COVID-19 vaccine to the medical staff at Yamagata University Hospital from March to August 2021. Subsequently, we conducted an online questionnaire-based survey to investigate the presence of allergy and adverse reactions after vaccination and examine the association between allergy and adverse reactions after immunization. RESULTS: Responses were collected from 1586 to 1306 participants after the first and second administration of the BNT162b2 mRNA COVID-19 vaccine, respectively. Adverse reactions included injection site pain, injection site swelling, fever, fatigue or malaise, headache, chills, nausea, muscle pain outside the injection site, and arthralgia. The frequency of some adverse reactions and their severity were higher, and the duration of symptoms was longer in participants with allergies than in those without allergies. Although several participants visited the emergency room for treatment after the first and second vaccinations, no participant was diagnosed with anaphylaxis. CONCLUSIONS: This study suggests that the frequency and severity of adverse reactions after injection of BNT162b2 mRNA COVID-19 vaccine were higher in individuals with allergy; however, no severe adverse reactions such as anaphylaxis or death were observed. These results indicate that individuals with allergic histories may tolerate the BNT162b2 mRNA COVID-19 vaccine.

Effect of hyperhomocysteinemia on a murine model of smoke-induced pulmonary emphysema.

Hyperhomocysteinemia was reported to enhance endoplasmic reticulum (ER) stress and subsequent apoptosis in several cells. However, the precise mechanisms of smoking susceptibility associated with hyperhomocysteinemia has not been fully elucidated. This study included 7- to 9-week-old C57BL6 male mice induced with hyperhomocysteinemia and were exposed to cigarette smoke (CS). A549 cells (human alveolar epithelial cell line) were cultured with homocysteine and were exposed to cigarette smoke extract (CSE) to observe cell viability and expression of proteins related to the ER stress. After 6 months of CS exposure, pulmonary emphysema was more severely induced in the group under the condition of hyperhomocysteinemia compared to that in the control group. The apoptotic A549 cells increased as homocysteine concentration increased and that was enhanced by CSE. Protein expression levels of ER stress markers were significantly increased after simultaneous stimulation. Notably, vitamin B12 and folate supplementation improved ER stress after simultaneous stimulation of A549 cells. In this study, we showed that hyperhomocysteinemia exacerbates CS exposure-induced emphysema in mice, suggesting that hyperhomocysteinemia and CS stimulation enhance ER stress and subsequent induced apoptosis in alveolar epithelial cells. It was suggested that there is a synergistic effect between homocysteine and CS.

Immunohistochemical staining for transcription factor MafB in alveolar macrophages is correlated with spirometric measures of airflow limitation in smokers.

BACKGROUND AND OBJECTIVE: Alveolar macrophages (AM) play an important role in the pathogenesis of COPD, and their numbers are significantly increased in patients with COPD. We previously demonstrated that expression of the transcription factor, MafB, was upregulated in AM of mice exposed to cigarette smoke. The aim of this study was to investigate whether the expression of MafB is associated with the degree of airflow limitation (AFL) in smokers. METHODS: Lung tissue specimens were obtained from male patients undergoing resection of small peripheral lung tumours. The patients were classified into three groups according to smoking index and FEV1 /FVC: (i) non-smokers or non-heavy ex-smokers without AFL (FEV1 /FVC ≥ 0.7, smoking index ≤ 400) (n=8); (ii) heavy current smokers without AFL (FEV1 /FVC ≥ 0.7, smoking index ≥ 800) (n=8); and (iii) heavy current smokers with AFL (FEV1 /FVC < 0.6, smoking index ≥ 800) (n=8). The intensity of immunostaining for MafB in AM was quantified by image analysis. RESULTS: Immunostaining for MafB was significantly enhanced in AM of smokers with AFL compared with AM of subjects without AFL. Smoking index, FEV1/FVC and FEF(25-75%) (% predicted) were significantly correlated with the intensity of MafB immunostaining. Multiple linear regression analysis revealed that FEV1 % was also an independent negative predictor of the intensity of MafB immunostaining. CONCLUSIONS: The degree of immunostaining for MafB in AM was correlated with the degree of AFL in smokers. MafB may be involved in the pathophysiology of COPD.