Impaired nuclear factor erythroid 2-related factor 2 expression increases apoptosis of airway epithelial cells in patients with chronic obstructive pulmonary disease due to cigarette smoking.

BACKGROUND: Cigarette smoking-induced oxidative stress is known to be a key mechanism in COPD pathogenesis. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a central transcription factor that regulates the antioxidant defense system. The aim of this study was to compare Nrf2 expression in COPD subjects and control subjects, and to determine the role of Nrf2 in protecting against oxidative stress-induced apoptosis. METHODS: We enrolled 8 COPD subjects and 7 control subjects in this study. We performed bronchial brushing by bronchoscopy and obtained bronchial epithelial cells from the airways. Nrf2 expression in bronchial epithelial cells was evaluated by real-time PCR and Western blotting. We examined the effect of 10 or 15 % cigarette smoke extract (CSE) induced A549 cells apoptosis using a time-lapse cell imaging assay with caspase-3/7 activation detecting reagent and performed Terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling assay for confirming A549 cells apoptosis. We also examined the effects of Nrf2 knockdown and, 0.1, 0.5, and 1.0 mM N-acetyl cysteine on CSE-induced apoptosis. Statistical analyses were performed using t-test, paired t-test or an analysis of variance followed by the Tukey-Kramer method. RESULTS: Nrf2 mRNA expression in COPD subjects was significantly lower than that in control subjects and Nrf2 mRNA were negatively correlated with pack year. Nrf2 protein in COPD subjects was significantly lower than that in control subjects. CSE-induced A549 cells apoptosis was increased in a time-, concentration-dependent manner, and was significantly increased by Nrf2 knockdown. N-acetyl cysteine significantly ameliorated CSE-induced apoptosis. CONCLUSIONS: Nrf2 expression was lower in COPD patients than in control subjects. Nrf2 might have a protective role against apoptosis caused by CSE-induced oxidative stress. These results suggest an involvement of Nrf2 in COPD and administration of antioxidants to patients with COPD might be a basic therapeutic option.

Up-regulation of the MicroRNA miR-30c Induced by High Mobility Group Box 1 in A549 Cells Used as an Alveolar Epithelial Model.

Background: MicroRNAs (miRNAs) have been reported to be involved in multiple diseases, including chronic obstructive pulmonary disease (COPD), a progressive disease in which alveolar apoptosis may play a role. We hypothesized that miRNAs are associated with the response to injury. induced by high mobility group box 1 (HMGB1), a cytokine crucial for the development of COPD, and studied the potential link between HMGB1 and miRNAs. Materials and Methods: A549 cells were stimulated with recombinant HMGB1. RNA and protein were extracted and culture supernatants were collected. Molecules downstream of HMGB1 signaling were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Expression levels of miRNA were analyzed by quantitative RT-PCR. Cellular injury was evaluated by western blotting of relevant proteins. Apoptosis was evaluated by in situ terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL). Results: HMGB1 treatment of A549 cells resulted in the up-regulation of tumor necrosis factor (TNF)-α and macrophage inflammatory protein (MIP)-2 mRNAs and over expression of matrix metalloprotease (MMP)-7 protein in the supernatant. The miRNA miR-30c was also up-regulated in response to HMGB1 treatment. Cellular injury and apoptosis were observed following HMGB1 treatment, as demonstrated by the oyerexpression of cyclin A2 (CCNA2) and phosphatase and tensin homolog (PTEN) proteins and-b'y decreased levels of pro-caspase-7 protein. The TUNEL assay showed that A549 cells with HMGB1 stimulation underwent apoptosis. Conclusions: Up-regulation of miR-30c and apoptosis of A549 cells were observed following HMGB1 stimulation. Our model demonstrates the potential for utilization of HMGB1 and miR-30c in further studies of alveolar apoptosis in COPD.

[Primary nasopharyngeal tuberculosis].

A 59-year-old female was complaining of sore throat, right otorrhea, and hearing impairment. There were no abnormal findings suggestive of pulmonary tuberculosis on her chest XP and CT. Nasopharyngoscopic examination detected a lesion coated with white mass on her nasopharynx, and a biopsy-specimen from this lesion revealed histopathological findings compatible with tuberculosis and the presence of acid-fast bacilli. PCR was positive for Mycobacterium tuberculosis complex. Therefore, we diagnosed the case as primary nasopharyngeal tuberculosis and treated her by 4-drug combination regimen with daily isoniazid, rifampicin, ethambutol and pyrazinamide. Later, low degree of resistance was noticed, isoniazid was replaced by levofloxacin. After the anti-tuberculosis chemotherapy, her symptoms almost completely diminished and the mass in her nasopharynx disappeared. As far as we can search, 23 Japanese cases of primary nasopharyngeal tuberculosis, including this case, have been reported in the literatures. We summarized the clinical features of these cases in Table. Nasopharyngeal tuberculosis is a rather rare disease. But, recently, due to the advances in diagnostic technology, the number of the case-reports has been increasing. Difficulties in detecting tubercle bacilli in nasopharyngeal lesion sometimes delayed definite diagnosis and treatment. If a patient complains the symptoms compatible with this disease, such as sore throat, pharyngeal pain and otorrhea, which are refractory to the general antibiotic therapy, we should be aware of the existence of this disease and repeat bacteriological and/or molecular examinations to prove tubercle bacilli to be able to start timely anti-tuberculosis chemotherapy.

[Twenty-one patients of malignant pleural mesothelioma in the Senshu district].

Twenty-one patients (15 men, 6 women, median age 67) were given a diagnosis of malignant pleural mesothelioma between March 1998 and December 2007 in our hospital. There was apparent occupational exposure of asbestos in 11 patients and suspicion of asbestos exposure in 5. Mean period recuired for diagnosis was 60 days with VATS and percutaneous needle biopsy. Eight patients underwent pleuropneumonectomy. Their median survival was 14.4 months, and the 2-year survival rate was approximately 30%. Seven other patients received chemotherapy, another patient underwent palliative radiotherapy and the remaining 5 patients received best supportive care. One patient had long survived (41.6 months) with gemcitabine-based chemotherapy. In the Senshu district, in the southern part of Osaka, there have been many asbestos spinning mills, so environmental exposure might occur. We should try to diagnose malignant mesothelioma for patients with pleural effusion even if they apparently do not have a history of asbestos exposure.