Exercise Ameliorates Emphysema Of Cigarette Smoke-Induced COPD In Mice Through The Exercise-Irisin-Nrf2 Axis.

Background: Oxidative stress is one of the important mechanisms underlying the pathogenesis of chronic obstructive pulmonary disease (COPD). Irisin is a type of myokine secreted from the muscle during exercise and acts against oxidative stress via nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor with antioxidant properties. Here, we examined the emphysema suppressive effects of the exercise-irisin-Nrf2 axis in mice. Methods: Mice were divided into three groups, namely, the control, smoking, and exercise + smoking groups. All mice from the smoking and exercise + smoking groups were exposed to cigarette smoke once a day. The mice from the exercise + smoking group were adapted to a treadmill once a day. To investigate the Nrf2 cascade, after 12 weeks, serum irisin concentration and Nrf2 and heme oxygenase-1 (HO-1) expression in the lung homogenate were determined. To evaluate cigarette smoke-induced COPD, the number of inflammatory cells in bronchoalveolar lavage fluid (BALF), mean linear intercept (MLI), and destructive index in the lung tissue were examined. Results: Serum irisin concentration and the expression levels of Nrf2 and HO-1 in the lung homogenate were significantly higher in mice from the exercise + smoking group than in those from the control and smoking groups. The proportion of neutrophils in the BALF was significantly lower in the exercise + smoking group than in the smoking group. The MLI and destructive index were also significantly smaller in mice from the exercise + smoking group than mice from the smoking group. Conclusion: Irisin secreted from the muscle during exercise may exert protective effects against oxidative stress via Nrf2 and HO-1, and ameliorate emphysema of cigarette smoke-induced COPD. The exercise-irisin-Nrf2 axis may serve as a novel target for COPD treatment.

Astaxanthin Suppresses Cigarette Smoke-Induced Emphysema through Nrf2 Activation in Mice.

Oxidative stress plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). The activation of nuclear factor erythroid 2-related factor 2 (Nrf2) is a key cellular defense mechanism against oxidative stress. Recent studies have shown that astaxanthin protects against oxidative stress via Nrf2. In this study, we investigated the emphysema suppression effect of astaxanthin via Nrf2 in mice. Mice were divided into four groups: control, smoking, astaxanthin, and astaxanthin + smoking. The mice in the smoking and astaxanthin + smoking groups were exposed to cigarette smoke for 12 weeks, and the mice in the astaxanthin and astaxanthin + smoking groups were fed a diet containing astaxanthin. Significantly increased expression levels of Nrf2 and its target gene, heme oxygenase-1 (HO-1), were found in the lung homogenates of astaxanthin-fed mice. The number of inflammatory cells in the bronchoalveolar lavage fluid (BALF) was significantly decreased, and emphysema was significantly suppressed. In conclusion, astaxanthin protects against oxidative stress via Nrf2 and ameliorates cigarette smoke-induced emphysema. Therapy with astaxanthin directed toward activating the Nrf2 pathway has the potential to be a novel preventive and therapeutic strategy for COPD.

Isoflavone Aglycones Attenuate Cigarette Smoke-Induced Emphysema via Suppression of Neutrophilic Inflammation in a COPD Murine Model.

Chronic obstructive pulmonary disease (COPD), a lung disease caused by chronic exposure to cigarette smoke, increases the number of inflammatory cells such as macrophages and neutrophils and emphysema. Isoflavone is a polyphenolic compound that exists in soybeans. Daidzein and genistein, two types of isoflavones, have been reported to have anti-inflammatory effects in various organs. We hypothesized that the daidzein-rich soy isoflavone aglycones (DRIAs) attenuate cigarette smoke-induced emphysema in mice. Mice were divided into four groups: the (i) control group, (ii) isoflavone group, (iii) smoking group, and (iv) isoflavone + smoking group. The number of inflammatory cells in the bronchoalveolar lavage fluid (BALF) and the airspace enlargement using the mean linear intercept (MLI) were determined 12 weeks after smoking exposure. Expressions of neutrophilic inflammatory cytokines and chemokines were also examined. In the isoflavone + smoking group, the number of neutrophils in BALF and MLI was significantly less than that in the smoking group. Furthermore, the gene-expressions of TNF-α and CXCL2 (MIP-2) in the isoflavone + smoking group were significantly less than those in the smoking group. Supplementation of the COPD murine model with DRIAs significantly attenuates pathological changes of COPD via suppression of neutrophilic inflammation.

Mediastinal peripheral T-cell lymphoma diagnosed by repeated biopsies after an initial diagnosis of fibrosing mediastinitis.

We report a case of mediastinal peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) diagnosed by repeated biopsies. A 44-year-old man was admitted to our hospital with a 2-week history of facial swelling, neck distension, and dyspnoea on exertion. Computed tomography of the chest showed a mediastinal mass. Initial needle biopsy and video-assisted thoracoscopic biopsy revealed the pathological diagnosis of fibrosing mediastinitis (FM). Glucocorticoid therapy (prednisolone) was temporarily effective in reducing tumour size. However, other laboratory features suggested that the diagnosis of FM might not be correct. After repeated biopsies, we established the diagnosis of mediastinal PTCL-NOS. With this correct diagnosis, appropriate therapy for PTCL resulted in the improvement of the clinical manifestations. This report suggests that the presence of malignant lymphoma should be considered in cases of mediastinal tumours, and repeated biopsies may be occasionally needed for consistent diagnosis.

latrogenic Mediastinal Emphysema and Subcutaneous Emphysema Induced by Bronchoscopic Examination.

A 79-year-old man presented with fever of unknown origin with interstitial shadows in the bilateral lung fields. A bronchoscopic examination did not indicate any malignancy or specific interstitial disease. After the bronchoscopic examination, the patient gradually developed subcutaneous and mediastinal emphysema. As the subcutaneous emphysema and mediastinal emphysema were mild, the patient was not administered any specific treatment. However, he eventually developed severe subcutaneous emphysema and mediastinal emphysema, and did not show any transient improvement. The patient underwent another bronchoscopic examination at another centre and a lacerated wound was detected. Thereafter, emergent operation was performed.

Primary Pleural Synovial Sarcoma Treated with Pazopanib.

A 42-year-old woman presented with chest pain and breathlessness with a nodule measuring 2×2 cm in size at the base of the right lung. A bronchoscopic examination did not reveal any malignancy. However, the patient developed difficulty in breathing, enlargement of the nodule, and right pleural effusion 14 days later. A video-assisted thoracic surgical biopsy specimen revealed the presence of pleural synovial sarcoma. The patient was treated with doxorubicin-ifosfamide combination chemotherapy because of metastasis to the pelvis. However, after a transient partial clinical response, there was a relapse of refractory disease. Although treated with pazopanib as second-line chemotherapy, the patient died eight months after the initial presentation.