Depletion of PD-1 or PD-L1 did not affect the mortality of mice infected with Mycobacterium avium.

The programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) pathway could affect antimicrobial immune responses by suppressing T cell activity. Several recent studies demonstrated that blocking of the PD-1/PD-L1 pathway exacerbated Mycobacterium tuberculosis infection. However, the effect of blocking this pathway in pulmonary Mycobacterium avium-intracellulare complex (MAC) infection is not fully understood. Wild-type, PD-1-deficient mice, and PD-L1-deficient mice were intranasally infected with Mycobacterium avium bacteria. Depletion of PD-1 or PD-L1 did not affect mortality and bacterial burden in MAC-infected mice. However, marked infiltration of CD8-positive T lymphocytes was observed in the lungs of PD-1 and PD-L1-deficient mice compared to wild-type mice. Comprehensive transcriptome analysis showed that levels of gene expressions related to Th1 immunity did not differ according to the genotypes. However, genes related to the activity of CD8-positive T cells and related chemokine activity were upregulated in the infected lungs of PD-1 and PD-L1-deficient mice. Thus, the lack of change in susceptibility to MAC infection in PD-1 and PD-L1-deficient mice might be explained by the absence of obvious changes in the Th1 immune response. Furthermore, activated CD8-positive cells in response to MAC infection in these mice seemed to not be relevant in the control of MAC infection.

Nrf2 Regulates Granuloma Formation and Macrophage Activation during Mycobacterium avium Infection via Mediating Nramp1 and HO-1 Expressions.

Nrf2 is a redox-sensitive transcription factor that is thought to be important in protection against intracellular pathogens. To determine the protective role of Nrf2 in the host defense against Mycobacterium avium complex (MAC), both wild-type and Nrf2-deficient mice were intranasally infected with MAC bacteria. Nrf2-deficient mice were highly susceptible to MAC bacteria compared with wild-type mice. There were no significant changes in the levels of oxidative stress and Th1 cytokine production between genotypes. Comprehensive transcriptome analysis showed that the expressions of Nramp1 and HO-1 were much lower in the infected lungs, and the expression of Nramp1 was especially lower in alveolar macrophages of Nrf2-deficient mice than of wild-type mice. Electron microscopy showed that many infected alveolar macrophages from Nrf2-deficient mice contained a large number of intracellular MAC bacteria with little formation of phagolysosomes, compared with those from wild-type mice. Treatment with sulforaphane, an activator of Nrf2, increased resistance to MAC with increased lung expression of Nramp1 and HO-1 in wild-type mice. These results indicate that Nramp1 and HO-1, regulated by Nrf2, are essential in defending against MAC infection due to the promotion of phagolysosome fusion and granuloma formation, respectively. Thus, Nrf2 is thought to be a critical determinant of host resistance to MAC infection.IMPORTANCE Nontuberculous mycobacteria (NTM) are an important cause of morbidity and mortality in pulmonary infections. Among them, Mycobacterium avium complex (MAC) is the most common cause of pulmonary NTM disease worldwide. It is thought that both environmental exposure and host susceptibility are required for the establishment of pulmonary MAC disease, because pulmonary MAC diseases are most commonly observed in slender, postmenopausal women without a clearly recognized immunodeficiency. However, host factors that regulate MAC susceptibility have not been elucidated until now. This study shows that Nrf2 is a critical regulator of host susceptibility to pulmonary MAC disease by promoting phagolysosome fusion and granuloma formation via activating Nramp1 and HO-1 genes, respectively. The Nrf2 system is activated in alveolar macrophages, the most important cells during MAC infection, as both the main reservoir of infection and bacillus-killing cells. Thus, augmentation of Nrf2 might be a useful therapeutic approach for protection against pulmonary MAC disease.

Sulforaphane ameliorates steroid insensitivity through an Nrf2-dependent pathway in cigarette smoke-exposed asthmatic mice.

Oxidative stress induced by cigarette smoke and other environmental pollutants contributes to refractory asthma. To better understand the role of smoking in asthma, we investigated the effects of cigarette smoke on allergic airway responses in mice and examined expression of nuclear factor-E2-related factor-2 (Nrf2) and its downstream factors, because Nrf2 is known to play a pivotal role in antioxidant responses. OVA-sensitized and challenged BALB/c mice were exposed to cigarette smoke and then treated with dexamethasone, sulforaphane (an activator of Nrf2), or their combination. Upon exposure to cigarette smoke, Nrf2 and associated transcripts were upregulated in response to oxidative stress, and asthmatic responses were steroid resistant. In OVA-sensitized and challenged mice exposed to cigarette smoke and treated with sulforaphane, Nrf2-mediated antioxidant responses were upregulated to a greater extent, and steroid sensitivity of asthmatic responses was restored. Moreover, the expression and activity of histone deacetylase 2 (HDAC2), a key regulator of steroid responsiveness, was reduced in mice exposed to cigarette smoke, but restored by sulforaphane treatment. No effects of sulforaphane were observed in Nrf2-deficient mice. These findings indicate that cigarette smoke induces steroid unresponsiveness in asthmatic airways, and that sulforaphane restores steroid sensitivity via upregulation of Nrf2 and enhancement of HDAC2 expression and activity. Thus, Nrf2 may serve as a potential molecular target for cigarette smoke-related refractory asthma resistant to steroid therapy.

Transcription Elongation Factor P-TEFb Is Involved in IL-17F Signaling in Airway Smooth Muscle Cells.

BACKGROUND: IL-17F is involved in the pathogenesis of several inflammatory diseases, including asthma and COPD. However, the effects of steroids on the function of IL-17F signaling mechanisms are largely unknown. One of the transcription elongation factors, positive transcription elongation factor b (P-TEFb) composed of cyclin T1 and cyclin-dependent kinase 9 (CDK9), is known as a novel checkpoint regulator of gene expression via bromodomain-containing protein 4 (Brd4). METHODS: Human airway smooth muscle cells were stimulated with IL-17F and the expression of IL-8 was evaluated by real-time PCR and ELISA. Next, the phosphorylation of CDK9 was determined by Western blotting. The CDK9 inhibitor and short interfering RNAs (siRNAs) targeting Brd4, cyclin T1, and CDK9 were used to identify the effect on IL-17F-induced IL-8 expression. Finally, the effect of steroids and its signaling were evaluated. RESULTS: IL-17F markedly induced the transcription of the IL-8 gene and the expression of the protein. Pretreatment of CDK9 inhibitor and transfection of siRNAs targeting CDK9 markedly abrogated IL-17F-induced IL-8 production. Transfection of siRNAs targeting Brd4 and cyclin T1 diminished IL-17F-induced phosphorylation of CDK9 and IL-8 production. Moreover, budesonide decreased CDK9 phosphorylation and markedly inhibited IL-17F-induced IL-8 production. CONCLUSIONS: This is the first report that P-TEFb is involved in IL-17F-induced IL-8 expression and that steroids diminish it via the inhibition of CDK9 phosphorylation. IL-17F and P-TEFb might be novel therapeutic targets for airway inflammatory diseases.

Discovery of a Fungal Multicopper Oxidase That Catalyzes the Regioselective Coupling of a Tricyclic Naphthopyranone To Produce Atropisomers.

Atropisomeric dinapinones A1 and A2 (DPA1 and DPA2) were isolated from a culture of Talaromyces pinophilus FKI-3864. Monapinone coupling enzyme (MCE), which dimerizes naphthopyranone monapinone A (MPA), was purified from a cell-free extract of T. pinophilus FKI-3864. MCE regioselectively dimerizes MPA at the 8,8'-positions to synthesize the atropisomers DPA1 and DPA2 in a ratio of approximately 1:2.5 without a cofactor. The optimal pH value and temperature for MCE were 4.0 and 50 °C, and the apparent Km and Vmax values for MPA were (72.7±23.2) µm and (1.21±0.170) µmol min-1 mg-1 protein. The MCE polypeptide is significantly homologous with multicopper oxidases. Heterologous expression of MCE and functional analysis confirmed that MCE catalyzes the regioselective coupling reaction of MPA to produce DPA. No fungal multicopper oxidase has previously been reported to catalyze regioselective intermolecular oxidative phenol coupling to produce naphthopyranone atropisomers.

Paradoxical response to osimertinib therapy in a patient with T790M-mutated lung adenocarcinoma.

A 'paradoxical response' to cancer treatment is a term used to describe the emergence of unexpected new lesions and the progression of existing lesions, despite appropriate and effective therapy. 'Pseudo-progression' is a phenomenon in which lymphocytes activated by an immune checkpoint inhibitor accumulate in a tumor and expand its shadow, mimicking enlargement of the primary lesion or development of a new metastatic lesion. Patients receiving cancer chemotherapy may respond differently to treatment, by exhibiting a response, deterioration, or the simultaneous occurrence of both. These variations may be attributed to the heterogeneity of the cancer. However, differences in the temporary response to epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) treatment are rarely observed. If such a phenomenon is observed, it should not affect the evaluation of the therapeutic effect or be considered as an indication for the discontinuation of treatment. We herein report a rare case of a transient increase in carcinomatous pleural fluid as a paradoxical response to osimertinib treatment in a patient with T790M-mutated lung adenocarcinoma. The primary lesion and pulmonary metastases responded well to therapy. Although this paradoxical response is very rare, of non-malignant nature, and does not usually require treatment modification of, physicians must acknowledge that it is not a clinically discouraging characteristic when using EGFR-TKI to treat T790M-mutated lung adenocarcinoma.

IL-17F induces IL-6 via TAK1-NFκB pathway in airway smooth muscle cells.

INTRODUCTION: Interleukin (IL)-17F plays a critical role in the pathophysiology of asthma. However, the precise role of IL-17F in airway smooth muscle cells (ASMCs) and its regulatory mechanisms remain to be defined. Therefore, we sought to investigate the expression of IL-6 by IL-17F and the involvement of transforming growth factor ß-activated kinase 1 (TAK1) and nuclear factor (NF)-κB by in ASMCs. METHODS: ASMCs were cultured in the presence or absence of IL-17F. The expression of IL-6 gene and protein was analyzed using real-time PCR and ELISA, and the activation of TAK1 and NF-κB was detected by Western blotting. The effect of TAK1 inhibitor 5Z-7-oxozeaenol and NF-κB inhibitor BAY 11-7082 on the expression of IL-6 was investigated. Finally, the short interfering RNAs (siRNAs) targeting TAK1 and a subunit of NF-κB, p65 were transfected into ASMCs. RESULTS: The expression of IL-6 gene and protein was significantly induced by IL-17F. IL-17F activated TAK1 and NF-κB in ASMCs. Transfection of siRNAs targeting TAK1 abolished IL-17F-induced phosphorylation of p65. Both 5Z-7-oxozeaenol and BAY 11-7082 significantly inhibited IL-17F-induced IL-6 production in a dose-dependent manner. Similarly, transfection of the cells with siRNAs targeting TAK1 and p65 inhibited the expression of IL-6. CONCLUSIONS: Collectively, these results provided evidence supporting the potential importance of the Th17-ASMCs crosstalk via the IL-17F-IL-6 axis in airway inflammation and as a candidate pharmacological target for airway inflammatory diseases such as asthma.

Sole metastatic pulmonary nodules from breast cancer simulating primary lung adenocarcinoma: Two case reports.

The characteristic radiological signs of primary lung adenocarcinoma include notching, lobulation, spicular formation, pleural indentation and a bronchus leading to the nodule (bronchus sign). However, metastatic tumors rarely display such characteristics. We herein present two cases of breast cancer with sole metastatic pulmonary tumors recurring ~20 years after surgery for breast cancer. These patients exhibited radiographic signs specific to primary lung adenocarcinoma. Pulmonary metastatic nodular lesions occur through hematogenous spread; therefore, obtaining pathological specimens by transbronchial biopsy may be challenging. In our patients, however, obtaining pathological specimens by transbronchial biopsy was feasible and it ultimately confirmed the diagnosis of lung metastasis from previously treated breast cancer. To the best of our knowledge, no similar cases are reported in the English medical literature. Therefore, metastatic breast cancer may exhibit the characteristic radiological signs of pulmonary lung adenocarcinoma and, although rare, pulmonary metastasis from breast cancer should be considered even in the presence of irregularly shaped pulmonary nodule(s) following long-term disease-free survival.

Elevated serum levels of two anti-neutrophil cytoplasmic antibodies in a lung cancer patient: A case report.

A 71-year-old woman with arthralgia and lung fibrosis was referred to Mito Kyodo General Hospital (Mito, Japan) for a mass, which was incidentally observed on a chest radiograph. The chest computed tomography scan demonstrated fibrotic lesions in the lower lobes of the lung and a nodule in the left upper lobe. The serum levels of myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA) and proteinase 3 (PR3)-ANCA were 60.3 and 7.5 U/ml, respectively. A transbronchial biopsy obtained from the nodule in the left upper lobe of the lung revealed a lung adenocarcinoma and the patient underwent standard upper lobectomy of the left lung. Subsequent to the resection, the serum levels of PR3-ANCA and MPO-ANCA returned to 10.0 and <1.0 U/ml, respectively. Notably, titers of antinuclear antibodies were also decreased during the postoperative course. Although elevated serum ANCA levels are rarely seen in lung cancer, they may be associated with the occurrence of lung cancer in certain patients, as observed in the present case.

Pemetrexed and bevacizumab-containing chemotherapy for pleomorphic carcinoma of the lung.

Pleomorphic carcinoma of the lung is a rare, highly malignant subtype of lung cancer, with a more aggressive clinical course compared with other types of non-small-cell lung cancer (NSCLC). Pemetrexed and bevacizumab are currently evaluated as two of the most reliable chemotherapeutic drugs for advanced NSCLC. We herein report a case of a 68- and a 46-year-old man with recurrent and chemo-naïve pleomorphic carcinoma of the lung, respectively, who were treated with a combination of carboplatin, pemetrexed and bevacizumab. The overall survival after the initiation of chemotherapy was 30 and 8 months, respectively. These cases exhibited a relatively long-term survival with chemotherapy. In the absence of definitive clinical trials, which are unlikely to be performed due to the rarity of this tumor, our cases demonstrated the potential utility of pemetrexed- and bevacizumab-containing chemotherapy. Our results also suggested that pemetrexed-containing chemotherapy may be key to the treatment of pleomorphic carcinoma of the lung.

Successful pemetrexed-containing chemotherapy for epidermal growth factor receptor mutation-positive adenosquamous cell carcinoma of the lung: A case report.

Pemetrexed-containing chemotherapy has shown promise in the treatment of non-small-cell lung cancer (NSCLC). However, although adenosquamous cell lung cancer (ASCLC) is a type of NSCLC, the availability of studies investigating its response to pemetrexed-containing chemotherapy is limited. A 66-year-old woman was referred to Mito Medical Center, University of Tsukuba with hemoptysis and a chest computed tomography (CT) scan revealed a large cavitary mass in the lower lobe of the left lung. The patient underwent left lower lobectomy and mediastinal lymph node dissection. The tumor was staged as pT2bN2M0. An epidermal growth factor receptor (EGFR) exon 19 deletion was identified in the adenocarcinomatous as well as the squamous cell carcinomatous components. Despite gefitinib therapy for pulmonary metastases, the patient developed cavitary metastases in both lungs. Therefore, treatment with pemetrexed-containing chemotherapy was initiated. A chest CT scan revealed significant regression of the metastatic lesions in both lungs, with thinning of the walls. The patient remains well and recurrence-free 19 months after the initiation of pemetrexed-containing chemotherapy. Therefore, the clinical response of EGFR mutation-positive ASCLC to pemetrexed-containing chemotherapy was promising, suggesting pemetrexed to be one of the key drugs for this subset of ASCLC patients.

A case study of bofutsushosan-induced pulmonary injury in a patient: Case report.

Bofutsushosan, a herbal (traditional Kampo) medicine, is administered to obese patients in North-East Asia. Bofutsushosan has been reported to exert various anti-obesity effects by stimulating the adipose tissue. The present study describes the case of a patient who developed a severe pulmonary injury that was potentially associated with bofutsushosan therapy. A 52-year-old woman was admitted to Mito Medical Center, University of Tsukuba, Mito Kyodo General Hospital (Mito, Japan) due to progressive dyspnea. Two months previously, bofutsushosan had been newly prescribed for her obesity. Bilateral ground-glass opacities and progressive respiratory deterioration suggested respiratory failure due to a therapeutic agent-induced lung injury. With discontinuation of bofutsushosan and the administration of a corticosteroid, an improvement in her respiratory condition was achieved, although sequelae remained in certain areas of the lungs. Resumption of other therapeutic agents did not reinduce the lung injury. Therefore, a diagnosis of bofutsushosan-induced lung injury was made. Although bofutsushosan-induced lung injury is particularly rare, clinicians should consider it when bofutsushosan is used.

Response to alectinib after one year of discontinuation of crizotinib in anaplastic lymphoma kinase-positive non-small-cell lung cancer: A case report.

Therapy with crizotinib achieves prolonged progression-free and overall survival in non-small-cell lung cancer (NSCLC) patients with echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK). It was demonstrated that ALK-positive NSCLCs exhibit a high response rate to the ALK inhibitor, crizotinib. However, a proportion of the patients discontinue crizotinib treatment due to adverse events. This is the case report of a NSCLC patient with EML4-ALK rearrangement, who, following crizotinib discontinuation for one year due to adverse events, exhibited a marked response to alectinib. Even if the incidence is not high, clinicians should not overlook the most common crizotinib-related adverse events. Furthermore, certain patients may continue to benefit from alectinib following long-term discontinuation of crizotinib therapy.

Synthetic double-stranded RNA induces interleukin-32 in bronchial epithelial cells.

OBJECTIVE: Interleukin (IL)-32 is a novel cytokine and is involved in the pathogenesis of various inflammatory diseases, including asthma and COPD. However, the regulatory mechanisms of IL-32 expression and its precise pathogenic role remain to be defined. Given that viral infections are known to potentially cause and exacerbate airway inflammation, in this study, we investigated the expression of IL-32 induced by synthetic double-stranded (ds) RNA, and its signaling mechanisms involved. METHODS: Bronchial epithelial cells were stimulated with synthetic dsRNA poly I:C. The levels of IL-32 expression were analyzed using real-time PCR and ELISA. The involvement of transforming growth factor ß-activated kinase 1 (TAK1) and a subunit of nuclear factor-κB (NF-κB), p65 was determined by western blot analyses. TAK1 inhibitor, 5Z-7-Oxozeaenol and NF-κB inhibitor, BAY 11-7082 were added to the culture to identify key signaling events leading to the expression of IL-32. Finally, the effect of short interfering RNAs (siRNAs) targeting TAK1 and p65 was investigated. RESULTS: dsRNA significantly induced IL-32 gene and protein expression, concomitant with activation of TAK1 and p65. Pretreatment of 5Z-7-Oxozeaenol diminished dsRNA-induced phosphorylation of NF-κB. Both 5Z-7-Oxozeaenol and BAY 11-7082 significantly abrogated dsRNA-induced IL-32 production. Moreover, transfection of the cells with siRNAs targeting TAK1 and p65 inhibited the expression of IL-32. CONCLUSIONS: The expression of IL-32 is induced by dsRNA via the TAK1-NF-κB signaling pathway in bronchial epithelial cells. IL-32 is involved in the pathogenesis of airway inflammation, and may be a novel therapeutic target for airway inflammatory diseases.

Superficial-type endobronchial metastases from colon cancer: A case report.

Certain internal malignancies, including colon cancer, can develop endobronchial metastasis. The present study reports a case of colon cancer with superficial-type endobronchial metastases in a 76-year-old male. Chest computed tomography revealed small masses and infiltrates in each lung, with bilateral hilar lymph node swelling. Superficial endobronchial tumors in each of the bronchi were unexpectedly found by bronchoscopic examination. A biopsy specimen obtained from the endobronchial tumor was diagnosed as colon cancer. Superficial-type endobronchial metastasis from colon cancer is extremely rare, however, such metastasis should be considered for patients who have a history of colon cancer. There should be no hesitation in performing a bronchoscopic biopsy as an additional examination.

Ossification and increased bone mineral density with zoledronic acid in a patient with lung adenocarcinoma: A case report.

Cases of ossification and increased bone mineral density (BMD) at sites of bone metastasis following zoledronic acid (ZA) treatment have not been reported. The current study presents the case of a 65-year-old patient with lung adenocarcinoma and bone metastases in the lumbar vertebrae and femurs. Ossification and an increase in BMD at the metastatic sites was achieved following treatment with ZA and irradiation of the bone metastatic sites. The patient was able to maintain a normal lifestyle for over two years, despite the bone metastases. Therefore, as treatment with ZA was demonstrated to improve patient quality of life, physicians should consider this treatment strategy, particularly for the treatment of metastasis in weight-bearing bones.

Skin metastasis from small cell lung cancer.

Patients with skin metastasis always had disseminated metastases in many organs. We herein report an unusual case with skin metastasis from small cell lung cancer (SCLC). The patient was treated with platinum-containing chemotherapy, and the response to the therapy was evaluated as partial response. The patient had slowly progressive disease and died of SCLC 16 months after the diagnosis of the diseases. If skin lesions, whether it may be typical or not, are found in SCLC patients, biopsy from the lesion would be considered to perform. Although trunk may be the most common sites, it is important to suspect such metastasis occurs in patients with SCLC.

Potential involvement of IL-17F in asthma.

The expression of IL-17F is seen in the airway of asthmatics and its level is correlated with disease severity. Several studies have demonstrated that IL-17F plays a pivotal role in allergic airway inflammation and induces several asthma-related molecules such as CCL20. IL-17F-induced CCL20 may attract Th17 cells into the airway resulting in the recruitment of additional Th17 cells to enhance allergic airway inflammation. We have recently identified, for the first time, that bronchial epithelial cells are its novel cell source in response to IL-33 via ST2-ERK1/2-MSK1 signaling pathway. The receptor for IL-17F is the heterodimeric complex of IL-17RA and IL-17RC, and IL-17F activates many signaling pathways. In a case-control study of 867 unrelated Japanese subjects, a His161 to Arg161 (H161R) substitution in the third exon of the IL-17F gene was associated with asthma. In atopic patients with asthma, prebronchodilator baseline FEV1/FVC values showed a significant association with the H161R variant. Moreover, this variant is a natural antagonist for the wild-type IL-17F. Moreover, IL-17F is involved in airway remodeling and steroid resistance. Hence, IL-17F may play an orchestrating role in the pathogenesis of asthma and may provide a valuable therapeutic target for development of novel strategies.

Retroperitoneal abscess shortly after chemotherapy for lung cancer: A case report.

To the best of our knowledge, the formation of a retroperitoneal abscess due to acute appendicitis shortly after administration of chemotherapy for lung cancer has not been previously reported. This is the case report of a 59-year-old male who was admitted to the Mito Medical Center (Mito, Japan) and diagnosed with lung adenocarcinoma with pleuritis carcinomatosis. Although no distant metastasis was identified, combination chemotherapy with cisplatin and pemetrexed was administered. Nine days after initiating chemotherapy, the patient developed right lower quadrant abdominal pain and high fever. Computed tomography (CT) of the abdomen and pelvis revealed the collection of gas and fluid in the retroperitoneum adjacent to the cecum. The abscess was locally drained; however, the infection continued to spread, with subsequent development of a scrotal abscess. Consequently, appendectomy was performed. The patient recovered well and the lung adenocarcinoma was treated with additional courses of chemotherapy following the remission of the local inflammation. Retroperitoneal abscess due to acute appendicitis is an unusual finding; however, this rare complication should be considered during or shortly after chemotherapy in patients with lung cancer.