Yoshinori Haruta

Airflow Limitation in Smokers Is Associated with Subclinical Atherosclerosis

RATIONALE Chronic obstructive pulmonary disease (COPD) is associated with increased morbidity and mortality from cardiovascular disease. Although a close association between COPD and atherosclerosis has been speculated, such scientific information is limited. OBJECTIVES To evaluate subclinical atherosclerosis in smokers with airflow limitation. METHODS The subjects of this study were healthy middle-aged men. Smokers with airflow limitation (n = 61) and age-matched control smokers (n = 122) and control never-smokers (n = 122) without airflow limitation were included in the present study. Subjects with diabetes, acute infection, and respiratory disease other than COPD were excluded beforehand. All subjects underwent chest radiogram, spirometry, blood sampling, and carotid ultrasonography. We determined carotid intima-media thickness and focal atheromatous plaque as indicators of subclinical atherosclerosis. MEASUREMENTS AND MAIN RESULTS Mean carotid intima-media thickness was greater in smokers with airflow limitation than in control smokers (P < 0.01) and control never-smokers (P < 0.005). Focal carotid plaque was significantly more prevalent in smokers with airflow limitation than in control never-smokers (P < 0.005). Multivariate analyses showed significant associations between thickened intima-media thickness and decreased percent predicted FEV(1) (P = 0.001) and between plaque and log(10) C-reactive protein (P = 0.013) independent of age, pack-years of smoking, body mass index, peripheral mean arterial pressure, heart rate, glucose, and low-density lipoprotein cholesterol. CONCLUSIONS Smokers with airflow limitation had exaggerated subclinical atherosclerosis. This study suggests that middle-aged men who are susceptible to COPD may also be susceptible to vascular atherosclerosis by smoking, and atherosclerotic change starts early in the disease process of COPD.

Suppression of plasminogen activator inhibitor-1 by RNA interference attenuates pulmonary fibrosis

Background and aim There is a growing body of evidence demonstrating that plasminogen activator inhibitor-1 (PAI-1) is involved in the progression of pulmonary fibrosis. In fact, PAI-1 knockout mice are protected from bleomycin-induced pulmonary fibrosis. This study was conducted to determine whether the intrapulmonary administration of small interfering RNA (siRNA) targeting PAI-1 (PAI-1-siRNA) limits the development of bleomycin-induced pulmonary fibrosis. Methods Lung biopsies from patients with idiopathic pulmonary fibrosis (IPF) were stained for PAI-1. The distribution of siRNA in the lung, the PAI-1 level in bronchoalveolar (BAL) fluid and the extent of fibrotic changes in the lung were evaluated following the intranasal administration of PAI-1-siRNA in a mouse model of bleomycin-induced pulmonary fibrosis. The effect of PAI-1-siRNA on the epithelial to mesenchymal transition (EMT) was also evaluated using a mouse lung epithelial cell line, LA-4. Results PAI-1 was overexpressed in the hyperplastic type 2 pneumocytes lining the honeycomb lesions of patients with IPF. The single intranasal instillation of PAI-1-siRNA resulted in the diffuse uptake of siRNA into the epithelial cells lining the dense fibrotic lesions. The repeated administration of PAI-1-siRNA initiated during either the inflammatory or the fibrotic phase into bleomycin-injured mice reduced the PAI-1 level in BAL fluid and limited the accumulation of collagen in the lungs. EMT induced by transforming growth factor β (TGFβ) in LA-4 cells was inhibited by transfection with PAI-1-siRNA. Conclusions The direct suppression of PAI-1 in the lung by the intrapulmonary administration of PAI-1-siRNA attenuated the development and progression of pulmonary fibrosis. The inhibition of EMT may be, at least in part, involved in this effect.

Tiotropium bromide is effective for severe asthma with noneosinophilic phenotype

To the Editor: Although currently available asthma medications are very effective in the majority of cases, there remains a subgroup for which disease control is difficult. Anticholinergics have long been used to treat asthma, although their current role in therapy is supplementary 1. Tiotropium bromide, a recently developed anticholinergic, is a long-acting bronchodilator with a well-established effectiveness for treating chronic obstructive pulmonary disease 2. Although some subgroups of asthmatics seem to respond better to anticholinergics, the pathophysiological features of these responders have yet to be established 3, 4. Previous studies that aimed to identify asthma subgroups which respond better to anticholinergics have suggested the following clinical features: patients with nocturnal symptoms, chronic asthma showing concurrent fixed airway obstruction, intrinsic asthma with longer duration of disease and nonatopic asthma 1, 5. The objective of the present study was to determine the characteristics of asthmatics which show good responses to tiotropium bromide. We investigated the efficacy of tiotropium bromide in …

Suppressor of cytokine signaling 1 inhibits pulmonary inflammation and fibrosis.

BACKGROUND Suppressor of cytokine signaling (SOCS) proteins are inhibitors of cytokine signaling. Our previous study suggested that SOCS1 regulates collagen synthesis by lung fibroblasts, suggesting a role of SOCS1 in the pathophysiology of pulmonary fibrosis. OBJECTIVES We sought to investigate the role of SOCS1 in pulmonary inflammation and fibrosis in vivo. METHODS SOCS1-haplodeficient mice treated with bleomycin (BLM) were evaluated for pulmonary inflammation and fibrosis compared with wild-type mice. The human study group was composed of 18 patients with interstitial lung disease. Lung specimens obtained by means of open lung biopsy were investigated to determine whether the severity of fibrosis was associated with decreased SOCS1 expression. Finally, we further analyzed the effect of exogenous SOCS1 on BLM-induced lung injury based on adenoviral SOCS1 gene transfer to the lung. RESULTS SOCS1-haplodeficient mice treated with BLM showed markedly enhanced pulmonary inflammation and fibrosis compared with wild-type mice. Using human lung specimens, we found that SOCS1 mRNA levels inversely correlated with duration of the disease. SOCS1 expression was significantly less in lung tissue from patients with idiopathic pulmonary fibrosis (IPF) compared with that in non-IPF patients. Moreover, SOCS1 expression was significantly less in severe fibrotic lesions (lower lobe) than in less fibrotic lesions (upper lobe). Adenoviral SOCS1 gene transfer to murine lungs significantly decreased lymphocytic inflammation, pulmonary fibrosis, and mortality because of BLM-induced lung injury. Exogenous SOCS1 inhibited expression of various cytokines, including TNF-alpha, which might play a key role. CONCLUSIONS These results suggest that SOCS1 might act as a suppressor for pulmonary fibrosis. SOCS1 might be a target of IPF treatment.

Anti-inflammatory effects and clinical efficacy of theophylline and tulobuterol in mild-to-moderate chronic obstructive pulmonary disease.

BACKGROUND The airway inflammation of chronic obstructive pulmonary disease (COPD) demonstrates a poor response to the anti-inflammatory actions of corticosteroids. However, long-acting beta(2)-agonists and low-dose theophylline are reported to have a possible anti-inflammatory effect in COPD. The aim of this study was to compare the effects of treatment between theophylline and the tulobuterol patch (transdermal patch preparation designed to yield sustained beta(2)-agonistic effects for 24h) on airway inflammation in addition to quality of life (QOL) and pulmonary function in mild-to-moderate COPD. METHODS The study subjects consisted of 26 patients with COPD who were treated with theophylline or tulobuterol for 8 weeks with a wash-out period of 4 weeks in a randomized open-label crossover study. We prospectively investigated the differential cell counts and levels of inflammatory markers in induced sputum before and after treatment with theophylline and tulobuterol. We also examined pulmonary function and quality of life (QOL) as assessed by St. Georges Respiratory Questionnaire. RESULTS In the induced sputum, the total inflammatory cell count and number of neutrophils were significantly reduced by treatment with low-dose theophylline. Neither of these parameters was significantly changed by treatment with tulobuterol. Pulmonary function measurements such as FEV(1), FEV(1) % pred, FVC, PEF, MEF(50), and MEF(25) were significantly improved by the treatment with low-dose theophylline but not tulobuterol. The total QOL scores, levels of interleukin 8 and myeloperoxidase in the supernatants of induced sputum, and serum levels of hypersensitive C-reactive protein were not significantly changed by either of the treatments. CONCLUSION These results suggest that treatment with low-dose theophylline but not the tulobuterol patch may have anti-inflammatory effects and improve pulmonary function in mild-to-moderate COPD.

Genetic ablation of the Bach1 gene reduces hyperoxic lung injury in mice: Role of IL-6

Bach1 is a transcriptional repressor of the heme oxygenase (HO)-1 gene. Bach1-null (Bach1(-/-)) mice are reported to be protected from myocardial ischemia/reperfusion injury; however, the effect of Bach1 disruption on another oxidative stress model of hyperoxic lung injury has yet to be determined. To investigate the role of Bach1 in hyperoxic lung injury, Bach1(-/-) mice and wild-type (WT) mice were exposed to 90% O(2). During hyperoxic exposure, the survival of Bach1(-/-) mice was significantly longer than that of WT mice. However, the administration of zinc protoporphyrin, an inhibitor of HO-1 activity, did not change the mortality in either of the mice, thus suggesting that this protective effect was not mediated by an HO-1 overexpression in Bach1(-/-) mice. The indices of lung injury in the lungs of Bach1(-/-) mice were lower than those of WT mice; unexpectedly, however, the levels of IL-6 in bronchoalveolar lavage (BAL) fluid from Bach1(-/-) mice were significantly higher than those of WT mice. Interestingly, the intrapulmonary administration of small interfering RNA against IL-6 was shown to reduce the IL-6 levels in BAL fluids and shorten the survival in Bach1(-/-) mice during hyperoxic exposure. In addition, a chromatin immunoprecipitation analysis revealed the binding of Bach1 to the IL-6 promoter and its detachment after oxidative stress. Considering the previous observation that the transgenic mice overexpressing IL-6 are protected from hyperoxic lung injury, these results therefore indicate that IL-6 mediates an increased survival in Bach1(-/-) mice during hyperoxic exposure.

Elevated serum IgE against MGL_1304 in patients with atopic dermatitis and cholinergic urticaria

BACKGROUND MGL_1304 secreted by Malassezia globosa is contained in human sweat and induces histamine release from basophils in patients with atopic dermatitis (AD) at a high positive rate. The aims of this study were to establish the enzyme-linked immunosorbent assay (ELISA) measuring specific immunoglobulins against MGL_1304 and to investigate the levels of these immunoglobulins in sera of patients with various allergic diseases. METHODS Purified MGL_1304 from human sweat (QRX) and recombinant MGL_1304 (rMGL_1304) were prepared for ELISA. To quantify the amount of MGL_1304-specific immunoglobulins, the standard serum was created by pooling sera of 20 patients with AD whose basophils released histamine in response to QRX. A monoclonal antibody which exhibited the highest neutralizing ability against QRX was established as Smith-2, and used as a capture antibody for the assay of QRX-specific IgE. A total of 156 subjects [normal controls (n = 23), AD (n = 63), cholinergic urticaria (CU) (n = 24), bronchial asthma (n = 32), and allergic rhinitis (n = 14)] were enrolled in this study. RESULTS ELISA methods to quantify the specific IgE, IgG and IgG4 against MGL_1304 in sera were successfully established. Levels of QRX-specific IgE in sera of patients with AD and CU were significantly higher than those of normal controls. Moreover, the levels of QRX-specific IgE and rMGL_1304-specific IgE in patients with AD were significantly correlated with their disease severities. CONCLUSIONS These ELISA methods to quantify the specific immunoglobulins against MGL_1304 are easy and useful means to assess allergy to MGL_1304. MGL_1304 contained in sweat is an important antigen for patients with AD and CU.

Levels of surfactant proteins A and D and KL-6 are elevated in the induced sputum of chronic obstructive pulmonary disease patients: a sequential sputum analysis.

Background: Recent clinical studies have suggested that serum surfactant protein (SP) A, SP-D and Krebs von den Lungen-6 (KL-6) are potential biomarkers for interstitial lung diseases. Serum levels of SP-A and SP-D have also been found to be elevated in chronic obstructive pulmonary disease (COPD), but their significance has not been evaluated or compared in induced sputum samples obtained directly from the airways. Objective: A sequential sputum analysis was conducted to assess the value of SP-A, SP-D and KL-6 levels in COPD. Methods: The study material consisted of induced sputum samples from 61 subjects, 28 with COPD and 33 with prolonged cough (cough lasting >3 weeks and normal spirometry). Sputum was collected in 3 fractions (3 periods of 5 min each). Sputum levels of these proteins were measured, and receiver operating characteristic curve analysis was carried out to evaluate the sensitivity, specificity and area under the curve (AUC) for each fraction. Results: The levels of SP-A, SP-D and KL-6 were higher in patients with COPD than in those with prolonged cough in each of the fractions. Sputum levels of these proteins correlated inversely with obstruction and positively with ageing, smoking history, sputum macrophages and eosinophils. Sputum fractionation had a relatively minor effect on the levels and AUC of these proteins. Conclusion: Sequential sputum analysis from 3 consecutive fractions indicated a significant difference in the levels of SP-A, SP-D and KL-6 between COPD and prolonged cough. However, sputum fractionation itself had a relatively minor effect on the levels of these proteins.

Circulating natural killer T cells in patients with asthma.

Recent studies suggest that therapies targeted at depletion or limiting of natural killer (NK) T cells may be a possible strategy for the treatment of asthma. In the present study, we measured the number of circulating Vα24+NKT cells in 32 asthmatic patients and compared these patients with 29 nonatopic healthy controls. We investigated the relationships between NKT cell number and clinical variables such as the number of eosinophils, the circulating level of IgE, and the severity of asthma. In addition, we also investigated the ability of NKT cells to proliferate in response to α‐galactosyl ceramide (α‐GalCer) in vitro. The Vα24+NKT cell counts of asthmatic patients were significantly lower than those of healthy controls. There were no significant differences observed in asthmatic patients among the subgroups in terms of atopic status and severity. There was no significant correlation between the number of NKT cells and clinical variables. The proliferative response to α‐GalCer of the patients and controls was not significantly different, indicating no intrinsic proliferative defect of NKT cells in asthma. These results suggest that the number of circulating NKT cells was already decreased in patients with asthma. Further study, such as the evaluation of lung NKT cells, will be needed to determine the role of NKT cells in patients with asthma.

IL‐12p40 is essential for the down‐regulation of airway hyperresponsiveness in a mouse model of bronchial asthma with prolonged antigen exposure

Background We previously reported a mouse model of bronchial asthma showing eosinophilic inflammation, but not airway hyperresponsiveness (AHR), after prolonged antigen exposure. This model showed an increase of IL‐12 in the lung.