Proximal and Distal Bronchioles Contribute to the Pathogenesis of Non-Cystic Fibrosis Bronchiectasis.

Rationale: Non-cystic fibrosis bronchiectasis (NCFB) may originate in bronchiolar regions of the lung. Accordingly, there is a need to characterize the morphology and molecular characteristics of NCFB bronchioles. Objectives: Test the hypothesis that NCFB exhibits a major component of bronchiolar disease manifest by mucus plugging and ectasia. Methods: Morphologic criteria and region-specific epithelial gene expression, measured histologically and by RNA in situ hybridization and immunohistochemistry, identified proximal and distal bronchioles in excised NCFB lungs. RNA in situ hybridization and immunohistochemistry assessed bronchiolar mucus accumulation and mucin gene expression. CRISPR-Cas9-mediated IL-1R1 knockout in human bronchial epithelial cultures tested IL-1α and IL-1ß contributions to mucin production. Spatial transcriptional profiling characterized NCFB distal bronchiolar gene expression. Measurements and Main Results: Bronchiolar perimeters and lumen areas per section area were increased in proximal, but not distal, bronchioles in NCFB versus control lungs, suggesting proximal bronchiolectasis. In NCFB, mucus plugging was observed in ectatic proximal bronchioles and associated nonectatic distal bronchioles in sections with disease. MUC5AC and MUC5B mucins were upregulated in NCFB proximal bronchioles, whereas MUC5B was selectively upregulated in distal bronchioles. Bronchiolar mucus plugs were populated by IL-1ß-expressing macrophages. NCFB sterile sputum supernatants induced human bronchial epithelial MUC5B and MUC5AC expression that was >80% blocked by IL-1R1 ablation. Spatial transcriptional profiling identified upregulation of genes associated with secretory cells, hypoxia, interleukin pathways, and IL-1ß-producing macrophages in mucus plugs and downregulation of epithelial ciliogenesis genes. Conclusions: NCFB exhibits distinctive proximal and distal bronchiolar disease. Both bronchiolar regions exhibit bronchiolar secretory cell features and mucus plugging but differ in mucin gene regulation and ectasia.

Interpretations of SARS-CoV-2 IgM and IgG antibody titers in the seroepidemiological study of asymptomatic healthy volunteers.

INTRODUCTION: The usefulness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests in asymptomatic individuals has not been well validated, although they have satisfied sensitivity and specificity in symptomatic patients. In this study, we investigated the significance of IgM and IgG antibody titers against SARS-CoV-2 in the serum of asymptomatic healthy subjects. METHODS: From June 2020, we recruited 10,039 participants to the project named the University of Tokyo COVID-19 Antibody Titer Survey (UT-CATS), and measured iFlash-SARS-CoV-2 IgM and IgG (YHLO IgM and IgG) titers in the collected serum. For the samples with increased IgM or IgG titers, we performed additional measurements using Elecsys Anti-SARS-CoV-2 Ig (Roche total Ig) and Architect SARS-CoV-2 IgG (Abbott IgG) and investigated the reactivity to N, S1, and receptor binding domain (RBD) proteins. RESULTS: After setting the cutoff value at 5 AU/mL, 61 (0.61%) were positive for YHLO IgM and 104 (1.04%) for YHLO IgG. Few samples with elevated YHLO IgM showed reactivity to S1 or RBD proteins, and IgG titers did not increase during the follow-up in any samples. The samples with elevated YHLO IgG consisted of two groups: one reacted to S1 or RBD proteins and the other did not, which was reflected in the results of Roche total Ig. CONCLUSIONS: In SARS-CoV-2 seroepidemiological studies of asymptomatic participants, sufficient attention should be given to the interpretation of the results of YHLO IgM and IgG, and the combined use of YHLO IgG and Roche total Ig might be more reliable.

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.

Epidemiological study using IgM and IgG antibody titers against SARS-CoV-2 in The University of Tokyo, Japan (UT-CATS).

INTRODUCTION: The worldwide pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has continued to date. Given that some of the patients with coronavirus disease 2019 (COVID-19) are asymptomatic, antibody tests are useful to determine whether there is a previous infection with SARS-CoV-2. In this study, we measured IgM and IgG antibody titers against SARS-CoV-2 in the serum of asymptomatic healthy subjects in The University of Tokyo, Japan. METHODS: From June 2020, we recruited participants, who were students, staff, and faculty members of The University of Tokyo in the project named The University of Tokyo COVID-19 Antibody Titer Survey (UT-CATS). Following blood sample collection, participants were required to answer an online questionnaire about their social and health information. We measured IgG and IgM titers against SARS-CoV-2 using iFlash-SARS-CoV-2 IgM and IgG detection kit which applies a chemiluminescent immunoassay (CLIA) for the qualitative detection. RESULTS: There were 6609 volunteers in this study. After setting the cutoff value at 10 AU/mL, 32 (0.48%) were positive for IgG and 16 (0.24%) for IgM. Of six participants with a history of COVID-19, five were positive for IgG, whereas all were negative for IgM. The median titer of IgG was 0.40 AU/mL and 0.39 AU/mL for IgM. Both IgG and IgM titers were affected by gender, age, smoking status, and comorbidities. CONCLUSIONS: Positive rates of IgG and IgM titers were relatively low in our university. Serum levels of these antibodies were affected by several factors, which might affect the clinical course of COVID-19.

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.

Early stage non-small cell lung cancer patients need brain imaging regardless of symptoms.

BACKGROUND: Japanese Lung Cancer Society and ESMO guideline recommends screening for brain metastasis in all patients with non-small cell lung cancer (NSCLC), while NCCN/ACCP guidelines do not recommend screening patients who are asymptomatic and with clinical stage I NSCLC. However, brain metastasis sometimes occurs in early stage NSCLC patients without any neurological symptoms. METHODS: We retrospectively reviewed medical records of 124 patients admitted to the University of Tokyo Hospital with stage IV NSCLC from January 2012 to April 2016. We analyzed clinical stage, the presence of the central nervous system manifestations and the number of brain metastases. RESULTS: Forty-six out of 124 cases had brain metastasis at presentation. The brain metastasis group had larger number of female, never smokers and patients with EGFR mutation compared with extracranial metastasis group. Twenty-one of 35 adenocarcinoma cases with brain metastasis had EGFR mutations. Out of 46 brain metastasis patients, 29 patients (63%) were asymptomatic and patients with EGFR mutations were significantly less likely to have neurological symptoms (4/21 vs. 7/14, p = 0.049). Six out of 46 cases with brain metastasis (13%) were clinical T1-2aN0. In clinical T1-2aN0 cases, only one patient had neurological symptoms at presentation. CONCLUSION: In clinical T1-2aN0 lung cancer patients with brain metastasis, almost all patients were asymptomatic. Patients with EGFR mutations and brain metastasis were likely to be asymptomatic. Regardless of central nervous system symptoms, routine brain imaging seems warranted in all NSCLC patients, especially in areas where patients have a higher frequency of EGFR mutations.

Analysis of drug treatment outcome in clarithromycin-resistant Mycobacterium avium complex lung disease.

BACKGROUND: Although the isolation of clarithromycin (CAM)-resistant Mycobacterium avium complex (MAC) indicates a poor treatment outcome and increased mortality, there have been only a few reports on drug treatment for CAM-resistant MAC lung disease. We aimed to reveal the effectiveness of the continuation of a macrolide and the use of a multidrug regimen in the treatment of CAM-resistant MAC lung disease. METHODS: Among patients with MAC pulmonary disease as defined by the 2007 criteria of the American Thoracic Society and the Infectious Diseases Society of America statement, those with CAM-resistant MAC (minimum inhibitory concentration ≥32 µg/ml) isolated, newly diagnosed and treated from January 2009 to June 2013 were analysed in this study. Effectiveness was measured based on culture conversion rate and improvement of radiological findings. RESULTS: Thirty-three HIV-negative patients were analysed in this study. Twenty-six were treated with a regimen containing CAM or azithromycin (AZM), and 21 patients were treated with three or more drugs except macrolide. The median duration to be evaluated was 10.4 months after beginning the treatment regimen. Sputum conversion (including cases of inability to expectorate sputum) was achieved in 12 (36%) patients. Radiological effectiveness improved in 4 (12%) patients, was unchanged in 11 (33%) patients and worsened in 18 (55%) patients. In the multivariate analysis, CRP <1.0 mg/dl (p = 0.017, odds ratio 12, 95% confidence interval (CI) 1.6-95) was found to be the only significant risk factor for radiological non-deterioration, and no significant risk factors for microbiological improvement were found. CONCLUSIONS: Our results suggested that continuation of macrolides or the addition of a new quinolone or injectable aminoglycoside to therapy with rifampicin and ethambutol would not improve clinical outcome after the emergence of CAM-resistant MAC. However, further prospective study is required to evaluate the precise clinical efficacy and effectiveness of these drugs.

[Retrospective Study of Clinical Features and Prognosis of Pneumococcal Pneumonia Among Patients Under 65 Years of Age].

The 23-valent pneumococcal polysaccharide vaccine (PPSV23) for elderly people has been included in the National Immunization Program (NIP) of Japan since October 2014. Targets for PPSV23 were restricted to persons ≥65 years of age and persons 60 to 64 years of age with an underlying severe physical disability (expressed as 1st grade in Japan). In this study, the clinical courses of non-target persons <65 years of age were compared between those with non-severe underlying diseases (A group) and those without underlying diseases (B group), and the need to expand the targets for PPSV23 within the NIP was investigated. Persons with pneumococcal pneumonia who were diagnosed based on a positive sputum or blood culture result were enrolled between January 2004 and April 2014. As a result, the number of subjects in A group was 2.6 times larger than that in B group, and this difference was especially pronounced (4.2 times) among subjects between the age of 60 to 64 years. These findings suggest that persons with underlying disease without a 1st grade physical disability might also be susceptible to pneumococcal pneumonia. No significant differences in the severity of pneumonia, the length of treatment, or the rates of admission were seen between A group and B group. The severity of pneumonia and the rates of admission among targets of the NIP were significantly higher than those of A group. In conclusion, our study suggests that A group should also be included among the targets of the NIP and that all targets eligible to receive the pneumococcal vaccine within NIP should be inoculated.

A Japanese herbal medicine (kampo), hochuekkito (TJ-41), has anti-inflammatory effects on the chronic obstructive pulmonary disease mouse model.

Chronic obstructive pulmonary disease (COPD) is a progressive disease that is characterized by chronic airway inflammation. A Japanese herbal medicine, hochuekkito (TJ-41), is prominently used for chronic inflammatory diseases in Japan. This study aimed to analyze the anti-inflammatory effect of TJ-41 in vivo and its underlying mechanisms. We created a COPD mouse model using intratracheal administration of porcine pancreatic elastase and lipopolysaccharide (LPS) and analyzed them with and without TJ-41 administration. A TJ-41-containing diet reduced inflammatory cell infiltration of the lungs in the acute and chronic phases and body weight loss in the acute phase. In vitro experiments revealed that TJ-41 treatment suppressed the LPS-induced inflammatory cytokines in BEAS-2B cells. Furthermore, TJ-41 administration activated the AMP-activated protein kinase (AMPK) pathway and inhibited the mechanistic target of the rapamycin (mTOR) pathway, both in cellular and mouse experiments. We concluded that TJ-41 administration reduced airway inflammation in the COPD mouse model, which might be regulated by the activated AMPK pathway, and inhibited the mTOR pathway.