Relationship between serum IgA levels and low percentage forced expiratory volume in the first second in asthma.

Objective: Immunoglobulin A (IgA) is suggested to have pathogenic effects in respiratory inflammatory diseases, including asthma. We aimed to analyze the relationship between serum IgA, and clinical indicators and biomarkers of asthma.Methods: This study was a post hoc analysis of the NHOM Asthma Study. In this study, serum IgA was measured using serum samples stored. We determined an association between the serum IgA level and clinical variables and biomarkers using multivariate linear regression and analyzed the differences in clinical indices between IgA high- and IgA low-asthma.Results: In this study, 572 patients with asthma were included in the final analysis. Lower percentage forced expiratory volume in the first second (%FEV1), higher serum eotaxin levels, lower serum ST2 levels, and higher serum MIP-1ß levels, were independently and significantly associated with higher serum IgA levels among asthma patients by multivariate linear regression analysis (%FEV1, 95% confidence interval [CI], -8.18- -0.613, p < 0.05; eotaxin, 95% CI, 8.95-46.69, p < 0.001; ST2, 95% CI, -73.71- -7.37, p < 0.05; and MIP-1ß, 95% CI, 1.47-18.71, p < 0.05). Furthermore, IgA high-asthma (serum IgA ≥ 238 mg/dL, n = 270) and IgA low-asthma (serum IgA < 238 mg/dL, n = 302) were compared separately. %FEV1 was significantly lower, the percentage of atopy was higher, and serum MIP-1ß level was higher in IgA high-asthma.Conclusions: This study suggests that serum IgA may be involved in the worsening of asthma outcomes, as assessed by %FEV1 and enhanced inflammation via elevated serum MIP-1ß.

Anti-Inflammatory Effects of Japanese Herbal Medicine Hochuekkito in a Mouse Model of Acute Exacerbation of Chronic Obstructive Pulmonary Disease.

INTRODUCTION: The traditional Japanese herbal medicine hochuekkito (TJ-41) has been reported to ameliorate systemic inflammation and malnutrition in patients with chronic obstructive pulmonary disease (COPD). TJ-41 has also been known to have preventive effects against influenza virus infection. However, its role in the acute exacerbation of COPD (AECOPD) remains to be elucidated. Our previous study established a murine model of viral infection-associated AECOPD that was induced by intratracheal administration of porcine pancreatic elastase (PPE) and polyinosinic-polycytidylic acid [poly(I:C)]. Here, we used this model and investigated the effects of TJ-41 in AECOPD. METHODS: Specific pathogen-free C57BL/6J mice were used. A COPD model was induced by treating mice intratracheally with PPE on day 0. To generate the murine model of AECOPD, poly(I:C) was administered intratracheally following PPE treatment on days 22-24. Mice were sacrificed and analyzed on day 25. Mice were fed a diet containing 2% TJ-41 or a control diet. RESULTS: Daily oral intake of TJ-41 significantly decreased the numbers of neutrophils and lymphocytes in the bronchoalveolar lavage fluid (BALF), which was accompanied by decreased transcripts of CXC chemokines involved in neutrophil migration, viz., Cxcl1 and Cxcl2, in whole lung homogenates and reduced Cxcl2 concentration in BALF. CONCLUSION: This study demonstrates the anti-inflammatory effects of TJ-41 in a mouse model of AECOPD, suggesting the effectiveness of TJ-41 for the management of COPD. Clinical investigations evaluating the therapeutic efficacy of TJ-41 in AECOPD would be meaningful.

Integrin alpha 2 is associated with tumor progression and postoperative recurrence in non-small cell lung cancer.

BACKGROUND: Integrins are transmembrane proteins that mediate cell adhesion to extracellular matrix. Whereas expression of integrin alpha 2 is associated with motility, invasiveness and cellular differentiation in various tumors, the role of integrin alpha 2 in lung cancer has not been studied in detail. The aim of this study was to determine whether and how aberrant integrin alpha 2 expression in non-small cell lung cancer leads to different outcomes. METHODS: We measured expression of integrin alpha 2 by quantitative polymerase chain reaction in 100 samples collected from non-small cell lung cancer patients who had undergone surgical resection. We assigned patients to high and low expression groups and analyzed survival. Cellular morphology, adhesion, proliferation, migration and invasion were examined in human lung cancer cell lines. RESULTS: Among 100 cases, 41 were female, with a median age of 71 years. High expression of integrin alpha 2 in non-small cell lung cancer was associated with lower recurrence-free survival (P = 0.004). Overexpression of integrin alpha 2 in cell lines had no effect on cell proliferation or invasion but resulted in increased cell size (1416 µm2 versus 470 µm2 in H522 cells, P < 0.001; 1822 µm2 versus 1029 µm2 in H661 cells, P = 0.02), adhesion (P < 0.001 in H522 and H661 cells) and migration (gap area filled was 71% versus 36% in H522 cells, P < 0.001; 57% versus 26% in H661 cells, P = 0.001). These changes were suppressed by E7820, an inhibitor of integrin alpha 2. CONCLUSIONS: Integrin alpha 2 may play a significant role in lung cancer adhesion and migration, and may lead to a higher risk of recurrence.

Phenotype characterization and biomarker evaluation in moderate to severe type 2-high asthma.

BACKGROUND: There are two major pathological phenotypes of asthma, type 2 (T2)-high and T2-low asthma, which are important in determining treatment strategies. However, the characteristics and phenotypes of T2-high asthma have not yet been fully identified. OBJECTIVE: This study aimed to identify the clinical characteristics and phenotypes of patients with T2-high asthma. METHODS: This study used data from a nationwide asthma cohort study in Japan, NHOM Asthma Study. T2-high asthma was defined as a blood eosinophils count ≥ 300 /µL and/or fractional exhaled nitric oxide level ≥ 25 ppb, and the clinical characteristics and biomarkers were compared between T2-high and T2-low asthma. Furthermore, T2-high asthma was phenotyped via hierarchical cluster analysis using Ward's method. RESULTS: Patients with T2-high asthma were older, less likely to be female, had longer asthma duration, had lower pulmonary function, and had more comorbidities, including sinusitis and SAS. Patients with T2-high asthma showed higher serum thymus and activation-regulated chemokine and urinary leukotriene E4 levels and lower serum ST2 levels than those with T2-low asthma. There were four phenotypes among patients with T2-high asthma: Cluster 1 (youngest, early-onset, and atopic), Cluster 2 (long duration, eosinophilic, and low lung function), Cluster 3 (elderly, female-dominant, and late-onset), and Cluster 4 (elderly, late-onset, and asthma-COPD overlap-dominant). CONCLUSIONS: Patients with T2-high asthma have distinct characteristics and four distinct phenotypes, in which eosinophil-dominant Cluster 2 is the most severe phenotype. The present findings may be useful in precision medicine for asthma treatment in the future.

ASCL1 regulates super-enhancer-associated miRNAs to define molecular subtypes of small cell lung cancer.

Small cell lung cancer (SCLC) is a highly aggressive neuroendocrine tumor with dismal prognosis. Recently, molecular subtypes of SCLC have been defined by the expression status of ASCL1, NEUROD1, YAP1, and POU2F3 transcription regulators. ASCL1 is essential for neuroendocrine differentiation and is expressed in the majority of SCLC. Although previous studies investigated ASCL1 target genes in SCLC cells, ASCL1-mediated regulation of miRNAs and its relationship to molecular subtypes remain poorly explored. Here, we performed genome-wide profiling of chromatin modifications (H3K27me3, H3K4me3, and H3K27ac) by CUT&Tag assay and ASCL1 knockdown followed by RNA sequencing and miRNA array analyses in SCLC cells. ASCL1 could preferentially regulate genes associated with super-enhancers (SEs) defined by enrichment of H3K27ac marking. Moreover, ASCL1 positively regulated several SE-associated miRNAs, such as miR-7, miR-375, miR-200b-3p, and miR-429, leading to repression of their targets, whereas ASCL1 suppressed miR-455-3p, an abundant miRNA in other molecular subtypes. We further elucidated unique patterns of SE-associated miRNAs in different SCLC molecular subtypes, highlighting subtype-specific miRNA networks with functional relevance. Notably, we found apparent de-repression of common target genes of different miRNAs following ASCL1 knockdown, suggesting combinatorial action of multiple miRNAs underlying molecular heterogeneity of SCLC (e.g., co-targeting of YAP1 by miR-9 and miR-375). Our comprehensive analyses provide novel insights into SCLC pathogenesis and a clue to understanding subtype-dependent phenotypic differences.

Identification of ANXA2 on epithelial cells as a new receptor for secretory IgA using immunoprecipitation and mass spectrometry.

Secretory immunoglobulin A plays an important role in the protection against exogenous pathogens and antigens, but it has also been reported to have pathogenic potential. We previously found that secretory immunoglobulin A accumulated in the peripheral lungs during idiopathic pulmonary fibrosis and that transferrin receptor/CD71 was partially involved in secretory immunoglobulin A-induced inflammatory cytokine production in A549 cells. This study aimed to identify the receptor responsible for the induction of cytokine production by secretory immunoglobulin A-stimulated airway epithelial cells. To this end, immunoprecipitation followed by time-of-flight mass spectrometry and peptide mass fingerprinting were performed and Annexin A2 was detected as a novel receptor for secretory immunoglobulin A. Enzyme-linked immunosorbent assay demonstrated binding of secretory immunoglobulin A to Annexin A2, and flow cytometry showed robust expression of Annexin A2 on the surface of BEAS-2B cells, A549 cells, and normal human bronchial/tracheal epithelial cells. Experiments in A549 cells using Annexin A2 small interfering RNA and neutralizing antibodies suggested that Annexin A2 was partially involved in the production of interleukin-8/CXCL8 and C-C motif chemokine ligand 2/monocyte chemoattractant protein-1 induced by secretory immunoglobulin A. Immunohistochemistry using lung sections revealed clear expression of Annexin A2 on airway epithelial cells, although the staining remained equivalent in idiopathic pulmonary fibrosis, asthma, and healthy control lungs. In conclusion, we identified that Annexin A2 expressed in airway epithelial cells is a novel receptor for secretory immunoglobulin A, which is involved in cytokine synthesis.

Immunoglobulin A promotes IL-6 and IL-8 production, proliferation, and migration by the human bronchial smooth muscle cells.

Immunoglobulin A (IgA) is important in biological defense, mainly in the mucosal area, and plays pathogenic roles in various diseases by activating both inflammatory and structural cells. The current study aimed to validate the effects of IgA on the human bronchial smooth muscle cell (BSMC), which plays a major role in airway inflammation and remodeling. Serum IgA induced interleukin (IL)-6 and IL-8 production at both mRNA and protein levels, and enhanced cell proliferation and migration by the BSMCs. The synthetic phenotype markers were regulated and the contractile phenotype markers were downregulated by serum IgA. Mitogen-activated protein kinase, phosphatidylinositol 3-kinase/Akt, and nuclear factor-κB pathways were involved in IgA-induced IL-6 and IL-8 production. The BSMCs expressed transferrin receptor (TfR), and TfR siRNA transfection inhibited IL-6 and IL-8 production by serum IgA. In summary, serum IgA is a potent activator of the BSMCs at least partially via TfR.

Myeloid differentiation protein-2 has a protective role in house dust mite-mediated asthmatic characteristics with the proinflammatory regulation of airway epithelial cells and dendritic cells.

BACKGROUND: Myeloid differentiation protein-2 (MD-2) is a lipopolysaccharide-binding protein involved in lipopolysaccharide signalling via Toll-like receptor 4 (TLR4). TLR4 plays an essential role in HDM-mediated allergic airway inflammation. Moreover, MD-2 is structurally similar to Der f 2, a major allergen from house dust mite (HDM). OBJECTIVES: We aimed to clarify the role of MD-2 in the pathogenesis of HDM-mediated allergic airway inflammation. METHODS: Wild-type (WT), TLR4 knockout and MD-2 knockout mice were subjected to intranasal instillation of HDM extract, and asthmatic features were evaluated. We also evaluated gene sets regulated by MD-2 in HDM-treated airway epithelial cells and examined the function of dendritic cells from lymph nodes and from lungs. RESULTS: Aggravated allergic airway inflammation with increased airway hyperresponsiveness was observed in MD-2 knockout mice compared with WT and TLR4 knockout mice. Global gene expression analysis revealed an MD-2 regulated proinflammatory response and reconstituted TLR4 signalling in airway epithelial cells. The ability of dendritic cells to evoke an allergic immune response was enhanced in MD-2 knockout mice. CONCLUSIONS & CLINICAL RELEVANCE: MD-2 plays a protective role in HDM-induced airway allergy with the proinflammatory regulation of airway epithelial cells and dendritic cells. MD-2 may serve as a therapeutic target in the treatment of asthma.

Evaluation of cytokine levels in response to mitogen among HIV-1-infected blood cells and their relationships to the number of T cells.

BACKGROUND: Human immunodeficiency virus-1 (HIV-1) infection causes loss and anergy of CD4+ and CD8+ T cells, leading to opportunistic infections, including tuberculosis (TB). QuantiFERON®-TB (QFT) is used as a diagnostic tool to detect TB, but it exhibits limited accuracy among subjects with low CD4+ T cell numbers, including HIV-1-infected individuals. The present study aimed to determine the effect of HIV-1 infection and patients' blood T cell numbers on cytokine production in response to mitogen (Mit) stimulation. METHODS: The number of CD4+ and CD8+ T cells in HIV-1-infected individuals was quantified. Levels of various cytokines in Mit-stimulated and un-stimulated (Nil) supernatants of QFT gold "in tube" were assessed using a MAGPIX System. The correlation between cytokine levels and CD4+/CD8+ T cell counts in response to Mit was analyzed. The cytokine levels were compared between HIV-1-infected and healthy subjects. RESULTS: HIV-1-infected individuals (110) and control subjects (27) were enrolled. Interferon (IFN)-γ, interleukin-1 receptor antagonist (IL-1RA), IL-6, IL-8, and regulated on activation, normal T cell expressed and secreted (RANTES) values in Mit-Nil tubes showed a significant correlation with CD4+ T cell counts, while IFN-γ, IL-6, and IFN-γ-induced protein 10 (IP-10) values in Mit-Nil tubes had significant correlation with CD8+ T cell counts. IL-1RA, IL-8, IP-10, platelet-derived growth factor (PDGF)-BB, and RANTES levels in Nil tubes were significantly higher in the HIV-1-infected group. IFN-γ, IL-2, IL-5, IL-6, IP-10, and macrophage inflammatory protein-1ß values in Mit-Nil tubes were significantly higher, and PDGF-BB and RANTES levels were significantly lower in the HIV-1-infected group. CONCLUSION: The functions of HIV-1-infected T cells and uninfected T cells, such as spontaneous and responsive cytokine production in response to Mit, were different. Our findings may be useful for developing new clinical tools for patients with low T cell counts. Additionally, the study provides new insights into the pathogenesis of HIV-1 infection.

High serum cytokine levels may predict the responsiveness of patients with severe asthma to benralizumab.

OBJECTIVE: Benralizumab, a humanized monoclonal antibody against human IL-5 receptor alpha, is effective in treating eosinophilic severe asthma. However, patients' response to benralizumab varies widely. In this study, we aimed to identify a new serum biomarker to accurately predict benralizumab response. METHODS: Seventeen benralizumab-treated patients with severe eosinophilic asthma were enrolled. Blood samples were collected; pulmonary function tests were performed and questionnaires were disseminated at baseline and after 1, 2, 4, and 6 months of treatment. Blood cytokine levels were measured. Response was defined as an elevation in forced expiratory volume in 1 s of at least 10.4% from baseline after 4 months of treatment. RESULTS: There were nine respondents and eight non-respondents. The non-responders showed significantly higher baseline serum interferon-γ; interleukin (IL)-4, -5, -6, -7, and -12p70; IL-17/IL-17A; IL-17E/IL-25; IL-18/IL-1F4; chemokine (C-C motif) ligand (CCL)3/macrophage inflammatory protein (MIP)-1α; CCL4/MIP-1ß; CCL11/eotaxin; matrix metalloproteinase-12; tumor necrosis factor-α, and thymic stromal lymphopoietin levels. After benralizumab administration, the serum CCL3/MIP-1α and CCL11/eotaxin levels significantly and persistently increased in the responders (CCL3/MIP-1α, responders: 144.5 ± 37.9 pg/ml (baseline) vs. 210.3 ± 59.4 pg/ml (4 months), p = 0.009; non-responders: 270.8 ± 139.8 pg/ml (baseline) vs. 299.5 ± 159.9 pg/ml (4 months), p = 0.33; CCL11/eotaxin, responders: 167.9 ± 62.6 pg/ml (baseline) vs. 326.7 ± 134.4 pg/ml (4 months), p = 0.038; non-responders: 420.9 ± 323.1 pg/ml (baseline) vs. 502.1 ± 406.0 pg/ml (4 months), p = 0.30). CONCLUSION: Low baseline serum inflammatory cytokine levels may be useful in predicting a good benralizumab response.Supplemental data for this article is available online at at www.tandfonline.com/ijas .

Association between Inhalation Instruction Method in Community Pharmacies and Inhaler Device Handling Error in Patients with Obstructive Lung Disease: An Evaluation of the Impact of Practical Demonstration by Pharmacists.

Inhaler devices play an important role in the management of obstructive lung diseases including asthma, chronic obstructive pulmonary disease (COPD), and asthma-COPD overlap. Some of these patients show suboptimal inhaler techniques; however, time for inhaler instruction by pharmacists is limited in daily clinical practice. Therefore, sufficient education regarding inhaler device handling should be provided within a limited time frame. The current study aimed to investigate the instruction methods provided by community pharmacists and their influence on inhaler device handling techniques in outpatient clinical care settings. We retrospectively collected the data of outpatients with obstructive lung diseases who were referred to our hospital and who underwent inhalation technique assessments conducted by community pharmacists. The prevalence of handling errors, clinical characteristics of patients, and instruction methods were analyzed. In total, 138 patients (170 devices) were included in this study. Approximately 70.0% of patients received verbal explanations combined with leaflets about inhaler instructions. In a device-based analysis, 63 (37.1%) of 170 devices had at least one technical error and 18 (10.6%) of the devices had critical errors. Patients without critical errors received practical demonstration instructions from pharmacists combined with leaflets and verbal explanations more frequently than those with critical errors (22.8 vs. 0%, p < 0.01). This study revealed that patients with obstructive lung diseases commonly present with inhaler device handling errors and critical errors were observed with non-negligible frequency in daily practice in Japan. Combined instruction with leaflet, verbal explanation, and pharmacist demonstration may be effective in improving proper inhaler treatment.

Secretory Cells Dominate Airway CFTR Expression and Function in Human Airway Superficial Epithelia.

Rationale: Identification of the specific cell types expressing CFTR (cystic fibrosis [CF] transmembrane conductance regulator) is required for precision medicine therapies for CF. However, a full characterization of CFTR expression in normal human airway epithelia is missing. Objectives: To identify the cell types that contribute to CFTR expression and function within the proximal-distal axis of the normal human lung. Methods: Single-cell RNA (scRNA) sequencing (scRNA-seq) was performed on freshly isolated human large and small airway epithelial cells. scRNA in situ hybridization (ISH) and single-cell qRT-PCR were performed for validation. In vitro culture systems correlated CFTR function with cell types. Lentiviruses were used for cell type-specific transduction of wild-type CFTR in CF cells. Measurements and Main Results: scRNA-seq identified secretory cells as dominating CFTR expression in normal human large and, particularly, small airway superficial epithelia, followed by basal cells. Ionocytes expressed the highest CFTR levels but were rare, whereas the expression in ciliated cells was infrequent and low. scRNA ISH and single-cell qRT-PCR confirmed the scRNA-seq findings. CF lungs exhibited distributions of CFTR and ionocytes similar to those of normal control subjects. CFTR mediated Cl- secretion in cultures tracked secretory cell, but not ionocyte, densities. Furthermore, the nucleotide-purinergic regulatory system that controls CFTR-mediated hydration was associated with secretory cells and not with ionocytes. Lentiviral transduction of wild-type CFTR produced CFTR-mediated Cl- secretion in CF airway secretory cells but not in ciliated cells. Conclusions: Secretory cells dominate CFTR expression and function in human airway superficial epithelia. CFTR therapies may need to restore CFTR function to multiple cell types, with a focus on secretory cells.

Risk of drug-induced interstitial lung disease in hospitalised patients: a nested case-control study.

INTRODUCTION: Information on drug-induced interstitial lung disease (DILD) is limited due to its low incidence. This study investigated the frequencies of drug categories with potential risk in patients developing DILD during hospitalisation and analysed the risk of developing DILD associated with each of these drugs. METHODS: Using a Japanese national inpatient database, we identified patients without interstitial pneumonia on admission who developed DILD and required corticosteroid therapy during hospitalisation from July 2010 to March 2016. We conducted a nested case-control study; four controls from the entire non-DILD patient cohort were matched to each DILD case on age, sex, main diagnosis, admission year and hospital. We defined 42 classified categories of drugs with 216 generic names as drugs with potential risk of DILD, and we identified the use of these drugs during hospitalisation for each patient. We analysed the association between each drug category and DILD development using conditional logistic regression analyses. RESULTS: We retrospectively identified 2342 patients who developed DILD. After one-to-four case-control matching, 1541 case patients were matched with 5677 control patients. Six drug categories were significantly associated with the increased occurrence of DILD. These included epidermal growth factor receptor inhibitors (OR: 16.84, 95% CI 9.32 to 30.41) and class III antiarrhythmic drugs (OR: 7.01, 95% CI 3.86 to 12.73). Statins were associated with reduced risk of DILD (OR: 0.68, 95% CI 0.50 to 0.92). CONCLUSIONS: We demonstrated significant associations between various drug categories and DILD. Our findings provide useful information on drug categories with potential risk to help physicians prevent and treat DILD.

Factors affecting in-hospital mortality of non-tuberculous mycobacterial pulmonary disease.

BACKGROUND: The incidence and prevalence of non-tuberculous mycobacterial pulmonary disease (NTM-PD) are reportedly increasing in many parts of the world. However, there are few published data on NTM-PD-related death. Using data from a national inpatient database in Japan, we aimed in this study to identify the characteristics of patients with NTM-PD and clinical deterioration and to identify risk factors for in-hospital mortality. METHODS: We examined data from the Diagnosis Procedure Combination (DPC) database in Japan from July 2010 to March 2014. We extracted data for HIV-negative NTM-PD patients who required unscheduled hospitalization. We evaluated these patients' characteristics and performed multivariable logistic regression analysis to identify risk factors for all-cause in-hospital mortality. RESULTS: A total of 16,192 patients (median age: 78 years; women: 61.2%) were identified. The median body mass index (BMI) was 17.5 kg/m2 (IQR 15.4-20.0). All cause In-hospital death occurred in 3166 patients (19.6%). The median BMI of the patients who had died was 16.0 kg/m2 (IQR 14.2-18.4). Multivariable analysis revealed that increased mortality was associated with male sex, lower BMI, lower activities of daily living scores on the Barthel index, hemoptysis, and comorbidities, including pulmonary infection other than NTM, interstitial lung disease, pneumothorax, and malignant disease. CONCLUSIONS: We found associations between being underweight and having several comorbidities and increased in-hospital mortality in patients with NTM-PD. Preventing weight loss and management of comorbidities may have a crucial role in improving this disease's prognosis.

The Japanese Herbal (Kampo) Medicine Hochuekkito Attenuates Lung Inflammation in Lung Emphysema.

Chronic obstructive pulmonary disease (COPD) is a systemic inflammatory disorder. It often causes weight loss, which is considered a poor prognostic factor. A Japanese herbal Kampo medicine, Hochuekkito (TJ-41), has been reported to prevent systemic inflammation and weight loss in COPD patients, but the underlying biological mechanisms remain unknown. In the present study, we investigated the role of TJ-41 in vivo using a mouse model of lung emphysema. We used lung epithelium-specific Taz conditional knockout mice (Taz CKO mice) as the lung emphysema model mimicking the chronic pulmonary inflammation in COPD. Acute inflammation was induced by intratracheal lipopolysaccharide administration, simulating COPD exacerbation. Mice were fed a diet containing 2% TJ-41 or a control diet. Taz CKO mice showed increased numbers of inflammatory cells in the bronchoalveolar lavage fluid compared to control mice. This effect was reduced by TJ-41 treatment. In the acute exacerbation model, TJ-41 mitigated the increased numbers of inflammatory cells in the bronchoalveolar lavage fluid and attenuated lung inflammation in histopathological studies. Additional in vitro experiments using the human macrophage cell line U-937 demonstrated that lipopolysaccharide-induced tumor necrosis factor-alpha expression was significantly downregulated by TJ-41. These results suggest that TJ-41 has anti-inflammatory effects in lung emphysema both in the chronic phase and during an acute exacerbation. In conclusion, our study sheds light on the anti-inflammatory effects of TJ-41 in lung emphysema. This establishes its potential as a new anti-inflammatory therapy and a preventive medicine for exacerbations during the long-time maintenance of COPD patients.

Preoperative use of pirfenidone and reduced risk of postoperative severe respiratory complications in patients with idiopathic pulmonary fibrosis: Propensity score-matched analysis using a nationwide database in Japan.

BACKGROUND AND OBJECTIVE: Patients with idiopathic pulmonary fibrosis (IPF) often develop postoperative severe respiratory complications such as acute exacerbation. Pirfenidone, an oral anti-fibrotic drug, may reduce the incidence of such complications. However, the preventive effect of pirfenidone on postoperative severe respiratory complications remains unclear. METHODS: We identified patients with IPF who underwent surgery with general anaesthesia from July 2010 to March 2018 using the Diagnosis Procedure Combination database. We compared the occurrence of postoperative severe respiratory complications (receiving mechanical ventilation under endotracheal intubation and/or intravenous infusion of a high-dose corticosteroid and in-hospital death within 30 days after surgery) between patients who did and did not receive preoperative treatment with pirfenidone. Pearson's chi-square test and logistic regression analysis fitted with a generalized estimating equation were conducted in 1:4 propensity score-matched patients. RESULTS: Among 631 patients identified, 19% were treated with pirfenidone before surgery. The 30-day mortality rate was 3.1% and 1.7% in the control patients (n = 510) and pirfenidone-treated patients (n = 121), respectively. In the propensity score-matched population, preoperative treatment with pirfenidone was significantly associated with a lower proportion of postoperative severe respiratory complications (OR: 0.24; 95% CI: 0.07-0.76; p = 0.015). CONCLUSION: In this Japanese nationwide cohort, preoperative treatment with pirfenidone was significantly associated with a lower risk of postoperative severe respiratory complications in patients with IPF. Preoperative pirfenidone may thus be useful in preventing postoperative severe respiratory complications in patients with IPF who are planning to undergo surgery with general anaesthesia.

In-hospital mortality associated with community-acquired pneumonia due to methicillin-resistant Staphylococcus aureus: a matched-pair cohort study.

BACKGROUND: It remains unclear whether methicillin-resistant Staphylococcus aureus (MRSA) pneumonia is associated with higher mortality compared with non-MRSA pneumonia. This study's objective was to compare outcomes including in-hospital mortality and healthcare costs during hospitalisation between patients with MRSA pneumonia and those with non-MRSA pneumonia. METHODS: Using a national inpatient database in Japan, we conducted a 1:4 matched-pair cohort study of inpatients with community-acquired pneumonia from 1 April 2012 to 31 March 2014. In-hospital outcomes (mortality, length of stay and healthcare costs during hospitalisation) were compared between patients with and without MRSA infection. We performed multiple imputation using chained equations followed by multivariable regression analyses fitted with generalised estimating equations to account for clustering within matched pairs. All-cause in-hospital mortality and healthcare costs during hospitalisation were compared for pneumonia patients with and without MRSA infection. RESULTS: Of 450,317 inpatients with community-acquired pneumonia, 3102 patients with MRSA pneumonia were matched with 12,320 patients with non-MRSA pneumonia. The MRSA pneumonia patients had higher mortality, longer hospital stays and higher costs. Multivariable logistic regression analysis revealed that MRSA pneumonia was significantly associated with higher in-hospital mortality compared with non-MRSA pneumonia (adjusted odds ratio = 1.94; 95% confidence interval: 1.72-2.18; p < 0.001). Healthcare costs during hospitalisation were significantly higher for patients with MRSA pneumonia than for those with non-MRSA pneumonia (difference = USD 8502; 95% confidence interval: USD 7959-9045; p < 0.001). CONCLUSIONS: MRSA infection was associated with higher in-hospital mortality and higher healthcare costs during hospitalisation, suggesting that preventing MRSA pneumonia is essential.

Epithelial Expression of YAP and TAZ Is Sequentially Required in Lung Development.

TAZ (transcriptional coactivator with PDZ-binding motif) and YAP (Yes-associated protein) are key molecules of the Hippo pathway. Recent studies revealed that these molecules are essential in lung development; however, the precise signaling cascade involving these molecules and the differences in their roles during lung development remain unknown. We aimed to investigate YAP and TAZ functions using lung epithelium-specific Taz and Yap conditional knockout mice. We generated lung epithelium-specific Taz and Yap conditional knockout mice and investigated the functions of YAP and TAZ in lung development. Selective TAZ deficiency in mouse lung epithelial cells resulted in abnormal alveolarization, which mimics lung emphysema, in adults, whereas YAP deficiency caused disruption of bronchial morphogenesis during the embryonic stage. We report that TAZ and YAP are sequentially expressed in the lung and that this could explain their different phenotypes. Furthermore, we report that YAP stimulates Shh (Sonic hedgehog) expression and regulates the FGF (fibroblast growth factor)-SHH feedback loop, thereby contributing to normal bronchial morphogenesis. We also found that TGF-ß (transforming growth factor-ß) stimulation induced Shh expression in the lung epithelial cells, and both TAZ and YAP are essential in this novel pathway. Our results provide a novel insight into the molecular mechanisms underlying lung development and contribute to a better understanding of the characteristics of TAZ and YAP.

Active mTOR in Lung Epithelium Promotes Epithelial-Mesenchymal Transition and Enhances Lung Fibrosis.

The mTOR pathway is one of the key signal cascades in the pathogenesis of idiopathic pulmonary fibrosis. Previous studies have mainly focused on this pathway in the fibroblasts and/or myofibroblasts, but not in the epithelial cells. In this study, we sought to investigate the role of the mTOR pathway in lung epithelial cells in lung fibrosis. Using Sftpc-mTORSL1+IT transgenic mice, in which active mTOR is conditionally expressed in lung epithelial cells, we assessed the effects of chronically activated mTOR in lung epithelial cells on lung phenotypes as well as bleomycin-induced lung fibrosis. Furthermore, we isolated alveolar epithelial cell type 2 from mice and performed RNA sequencing. Sftpc-mTORSL1+IT transgenic mice had no obvious abnormal findings, but, after bleomycin administration, showed more severe fibrotic changes and lower lung compliance than control mice. RNA sequencing revealed Angptl4 (angiopoietin-like protein 4) as a candidate downstream gene of the mTOR pathway. In vitro studies revealed that ANGPTL4, as well as mTOR, promoted tight junction vulnerability and epithelial-mesenchymal transition. mTOR activation in lung epithelial cells promoted lung fibrosis and the expression of ANGPTL4, a novel downstream target of the mTOR pathway, which could be related to the etiology of fibrosis.

FOXL1 Regulates Lung Fibroblast Function via Multiple Mechanisms.

Fibroblasts provide a structural framework for multiple organs and are essential for wound repair and fibrotic processes. Here, we demonstrate functional roles of FOXL1 (forkhead box L1), a transcription factor that characterizes the pulmonary origin of lung fibroblasts. We detected high FOXL1 transcripts associated with DNA hypomethylation and super-enhancer formation in lung fibroblasts, which is in contrast with fibroblasts derived from other organs. RNA in situ hybridization and immunohistochemistry in normal lung tissue indicated that FOXL1 mRNA and protein are expressed in submucosal interstitial cells together with airway epithelial cells. Transcriptome analysis revealed that FOXL1 could control a broad array of genes that potentiate fibroblast function, including TAZ (transcriptional coactivator with PDZ-binding motif)/YAP (Yes-associated protein) signature genes and PDGFRα (platelet-derived growth factor receptor-α). FOXL1 silencing in lung fibroblasts attenuated cell growth and collagen gel contraction capacity, underscoring the functional importance of FOXL1 in fibroproliferative reactions. Of clinical importance, increased FOXL1 mRNA expression was found in fibroblasts of idiopathic pulmonary fibrosis lung tissue. Our observations suggest that FOXL1 regulates multiple functional aspects of lung fibroblasts as a key transcription factor and is involved in idiopathic pulmonary fibrosis pathogenesis.