Yoshikane Tokairin

Enhanced immediate inflammatory response to Streptococcus pneumoniae in the lungs of mice with pulmonary emphysema.

Background and objective:  Pulmonary emphysema is associated with frequent respiratory infections but little is known about the reasons for this susceptibility to bacterial infection. We previously demonstrated an impaired inflammatory response to Streptococcus pneumoniae in an experimental emphysema mouse model at 24 h, or longer following bacterial inoculation. Toll‐like receptors (TLR) have been recognized as regulators in the inflammatory response. We examined the expression of TLR on alveolar macrophages in experimental emphysema mice and evaluated the immediate inflammatory response of the emphysematous lung to streptococcal infection.

A novel polymorphism in CDC6 is associated with the decline in lung function of ex-smokers in COPD

The effect of smoking cessation on the rate of decline in lung function in patients with advanced stages of chronic obstructive pulmonary disease (COPD) has not been clarified. Saccharomyces cerevisiae cell division cycle 6 homolog (CDC6) protein possesses the pro-apoptotic properties. We tested our hypothesis that the individual susceptibility to rapid decline in lung function despite smoking cessation in patients with advanced stages of COPD is attributed to the genetic variants in the CDC6 gene. We prospectively followed 82 patients (ex-smokers) during 30months and evaluated the differences among the genotypes in the annual rate of decline in FEV(1.0) (%predicted) with ten single nucleotide polymorphisms (SNPs) in and around the CDC6 gene. We found significant differences in SNP5 (National Center for Biotechnology Information SNP reference: rs2077464), SNP6 (rs13706), SNP7 (rs7217852), and SNP8 (rs9904270) with a gene-dosage effect (ANOVA overall-P=0.029-0.030). The individual allele of SNP5G, SNP6A, SNP7G, and SNP8T were associated with rapid decline in FEV(1.0) (%predicted) [odds ratio (95% confidence interval)=2.35 (1.19-4.65), P=0.014]. The SNP5G/SNP6A/SNP7G/SNP8T haplotype was associated with an increased risk of deterioration of FEV(1.0) (%predicted) (P=0.017). Importantly, SNP6 caused a change in amino acids in CDC6 protein (Val441Ile), immediately upstream of the caspase-3-dependent cleavage site of CDC6 (Asp442) during apoptosis. These results suggest that CDC6 may be one of the susceptibility genes that contribute to rapid decline in lung function despite smoking cessation in these patients with COPD.

Clarithromycin Suppresses Invasiveness of Human Lung Adenocarcinoma Cells

Background: It has been speculated that clarithromycin (CAM), a 14-membered ring macrolide, possesses antitumor effects besides antimicrobial and anti-inflammatory effects. Method: We evaluated the effects of CAM on the growth and invasiveness of A549 lung adenocarcinoma cells. Results: Although CAM did not affect the growth of A549 cells, the Matrigel invasion assay showed that the potential of invasion was diminished by CAM treatment. When analyzed by flow cytometry, CAM suppressed α2- and β1-integrin expression. Furthermore, thymidine phosphorylase (TP) expression was diminished by CAM treatment in a dose-dependent manner. A specific TP inhibitor also suppressed β1-integrin expression in flow cytometric analysis. Conclusions: These results suggest that CAM may suppress invasive activity of A549 cells in part by diminishing the expression of TP, α2- and β1-integrin, which may be a downstream signal of the TP pathway, and that CAM could be useful in the treatment of lung adenocarcinoma.

Reference values of MostGraph measures for middle-aged and elderly Japanese individuals who participated in annual health checkups

BACKGROUND The forced oscillation technique (FOT) can measure respiratory system resistance and reactance under tidal volume respiration. MostGraph is a device that incorporates the FOT and enables the immediate, three-dimensional visualization of resistance and reactance parameters. The aim of this study was to establish MostGraph reference values for middle-aged and elderly Japanese individuals. METHODS From 2004 to 2006, 3253 subjects living in Takahata, Yamagata underwent spirometry. Of these, 872 again underwent spirometry in 2011, and 784 (368 men, ages 46-89 years; 416 women, ages 47-90 years) underwent FOT examinations using MostGraph-01. RESULTS In this study population, 19.0% of the men and 91.5% of the women were life-long never smokers. Abnormal spirometric findings were observed in 30.2% of the men and 14.6% of the women. Although the respiratory system resistance and reactance parameters obtained using MostGraph were not distributed normally, normal distribution was achieved via natural logarithm (R5, R20, Fres, and ALX), square root (R5-R20), or exponential (X5) transformation. Furthermore, the transformed values were converted back to the actual values after determining the values representing one and two standard deviations from the mean. CONCLUSION Respiratory system resistance and reactance reference values were determined using MostGraph in middle-aged and elderly Japanese individuals who participated in annual health checkups.

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.

Decreased left ventricular stroke volume is associated with low-grade exercise tolerance in patients with chronic obstructive pulmonary disease

Background Low-grade exercise tolerance is associated with a poor prognosis in patients with chronic obstructive pulmonary disease (COPD). The 6 min walk test (6MWT) is commonly used to evaluate exercise tolerance in patients with COPD. However, little is known regarding the relationship between cardiac function and exercise tolerance in patients with COPD. The aim of this study was to identify predictive factors in cardiac function for low-grade exercise tolerance in patients with stable COPD. Methods We recruited 57 patients with stable COPD (men 54, women 3) to perform the 6MWT. Patients with underlying orthopaedic disease or heart failure were excluded. Cardiac function was evaluated by echocardiography and contrast-enhanced cardiac CT. We also measured pulmonary function and the 6MWT distance. Results Forced expiratory volume in 1 s (FEV1) and per cent predicted FEV, along with left ventricular end diastolic volume and left ventricular cardiac output as measured by cardiac CT, were significantly related to the 6MWT distance. On multivariate analysis, left ventricular stroke volume was the factor most closely associated with a decreased walked distance in the 6MWT. Conclusions Decreased left ventricular stroke volume was associated with low-grade exercise tolerance in patients with stable COPD without heart failure.

Predictors for mortality from respiratory failure in a general population.

Risk factors for death from respiratory failure in the general population are not established. The aim of this study was to determine the characteristics of individuals who die of respiratory failure in a Japanese general population. In total, 3253 adults aged 40 years or older participated in annual health check in Takahata, Yamagata, Japan from 2004 to 2006. Subject deaths through the end of 2010 were reviewed; 27 subjects died of respiratory failure (pneumonia, n = 22; COPD, n = 1; pulmonary fibrosis, n = 3; and bronchial asthma, n = 1). Cox proportional hazard analysis revealed that male sex; higher age, high levels of D-dimer and fibrinogen; lower body mass index (BMI) and total cholesterol; and history of stroke and gastric ulcer were independent risk factors for respiratory death. On analysis with C-statistics, net reclassification improvement, and integrated discrimination improvement, addition of the disease history and laboratory data significantly improved the model prediction for respiratory death using age and BMI. In conclusion, we identified risk factors for mortality from respiratory failure in a prospective cohort of a Japanese general population. Men who were older, underweight, hypocholesterolemic, hypercoagulo-fibrinolytic, and had a history of stroke or gastric ulcer had a higher risk of mortality due to respiratory failure.

Prevalence of diabetes mellitus in individuals with airflow obstruction in a Japanese general population: The Yamagata-Takahata Study

BACKGROUND Diabetes has been reported as a comorbidity of chronic obstructive pulmonary disease (COPD) in Western countries, but it has not been demonstrated in epidemiological reports in Japan. The purpose of this study was to clarify whether the relationship between airflow obstruction and diabetes can be confirmed in a Japanese general population. METHODS From 2004 to 2006, blood sampling and pulmonary function tests were performed on 3045 people over the age of 40 years in annual health check-ups held in Takahata, Yamagata Prefecture, Japan. Pulmonary function was re-evaluated in 2009 and 2011. RESULTS The prevalence of diabetes did not differ between subjects with and without airflow obstruction. Furthermore, although body mass index decreased, no increase in the prevalence of diabetes was observed with the progression of airflow obstruction. The annual changes in forced expiration volume in 1s (FEV1) did not differ depending on the presence or absence of diabetes in the study population. CONCLUSION There was no difference in the prevalence of diabetes between subjects with airflow obstruction and those without. As patients with COPD in Japan are thinner than in the West, diabetes may not be a common comorbidity in Japanese patients with COPD.

MafB enhances efferocytosis in RAW264.7 macrophages by regulating Axl expression

The transcription factor MafB is involved in cellular differentiation and phagocytosis in macrophages. Macrophages phagocytose apoptotic cells in vivo; this process, which is known as efferocytosis, requires Axl receptor tyrosine kinase (Axl) activity. However, the association between MafB and efferocytosis, as well as that between MafB and Axl, in macrophages is unknown. We hypothesized that MafB modulates macrophage efferocytosis by regulating Axl expression. Fluorescent-labeled apoptotic thymocytes were added to RAW264.7-MafB-shRNA and control cells, and the proportion of phagocytosis-positivey fluorescence microscopy and flow cytometry. In addition, Axl mRNA and protein were quantified by real-time PCR and western blotting in each group. RAW264.7-MafB-shRNA cells were transfected with a plasmid expressing green fluorescent protein (GFP)-tagged Axl or a control empty plasmid expressing only GFP. The capacity for phagocytosis of apoptotic cells was assessed in GFP-positive cells gated based on fluorescence intensity. In RAW264.7-MafB-shRNA cells, capacity for phagocytosis of apoptotic thymocytes was significantly reduced compared with that of control cells, as determined by fluorescence microscope and flow cytometry. Axl mRNA and protein expression was significantly reduced in RAW264.7-MafB-shRNA cells relative to control cells. Furthermore, the capacity of RAW264.7-MafB-shRNA cells, transfected with an Axl-expressing plasmid, for phagocytosis of apoptotic thymocytes was significantly greater than that of cells transfected with the control plasmid. Collectively, the present findings indicate that MafB enhances efferocytosis by regulating Axl expression in RAW264.7 macrophages.

Heart-type fatty acid binding protein as a prognostic factor in patients with exacerbated chronic obstructive pulmonary disease

BACKGROUND The designation of some cardiac-specific proteins as prognostic biomarkers in chronic obstructive pulmonary disease (COPD) exacerbations suggest that the process of exacerbation involves cardiomyocyte injury. Among these cardiac biomarkers, heart-type fatty acid binding protein (h-FABP) is considered a very sensitive diagnostic marker for cardiomyocyte injury and a prognostic marker in chronic heart failure. However, the prognostic usefulness of h-FABP in patients with COPD remains unclear. METHODS Sixty-six patients were enrolled in this study. Subjects who recovered from COPD exacerbation and were discharged without needing home oxygen therapy were defined as the improved group. Those who died of the COPD exacerbations, were discharged but needed home oxygen therapy, or were transferred to a rehabilitation hospital for respiratory failure and the remaining aftereffects of exacerbation were defined as the unimproved group. RESULTS The improved and unimproved groups included 54 and 12 subjects, respectively. Compared with the improved group, the unimproved group had significantly higher white blood cell counts and alanine aminotransferase, lactate dehydrogenase, blood urea nitrogen (BUN), uric acid, potassium, and h-FABP levels, and significantly lower total protein and total cholesterol levels and estimated glomerular filtration rates, either at admission or during the early morning within 24h after admission. A multivariate analysis revealed that higher serum h-FABP and potassium levels were independently predictive of a poor prognosis following a COPD exacerbation, and a receiver operating characteristic curve analysis yielded a cutoff of 4.5ng/ml for predicting lack of improvement. CONCLUSION H-FABP may predict the outcomes of COPD exacerbation.