IL-17F Induces CCL20 in Bronchial Epithelial Cells

IL-17F plays a crucial role in airway inflammatory diseases including asthma, but its function has not been fully elucidated. CCL20 is also involved in allergic airway inflammation, while its regulatory mechanisms remain to be defined. To further identify a novel role of IL-17F, the expression of CCL20 by IL-17F in bronchial epithelial cells and the signaling mechanisms involved were investigated. Bronchial epithelial cells were stimulated with IL-17F, and the levels of CCL20 gene and protein measured, with the effects of the addition of various kinase inhibitors and siRNAs also investigated. IL-17F significantly induced the expression of CCL20 gene and protein. Pretreatment with inhibitors for MEK1/2, Raf1 and MSK1, and overexpression of a Raf1 dominant-negative mutant significantly diminished IL-17F-induced CCL20 production. Moreover, transfection of the siRNAs targeting MSK1, p90RSK, and CREB blocked CCL20 expression. These findings suggest that IL-17F is able to induce CCL20 via Raf1-MEK1/2-ERK1/2-MSK1/p90RSK-CREB signaling pathway in bronchial epithelial cells. The IL-17F/CCL20 axis may be a novel pharmacological target for asthma

<Orignal>The Relationship Between the Pharmacological Effects of Benzodiazepines and Their in vivo Binding Sites in the Brain of Rats.

ベンゾジアゼピン系薬剤とフェノバルビタール薬理作用と脳内分布との関連を生体内で調べるため, 60匹のラット(体重470～480 g)を3郡に分け, 3^H-diazepam, 3^H-flunitrazepamまたは3^H-ohenobarbital 5μciを投与した。それぞれのグループのラットは薬剤の静脈内投与後3分, 10分, または40分の時点で断頭し, 各組織の放射能を測定し, d.p.m/g・tissueに換算した。この結果, 3^H-diazepamの放射線量は脳幹および視床下部で他の大脳皮質に比べ有意に高かった。また, 3^H-phenobarbitalの脳内濃度は換与後40分経ってもほとんど低下しなかった。これらの結果はベンゾジアゼピン系薬剤の薬理作用との密接な関連があり, in-vitroで証明されたbenzobiazepinereceotorはin-vivoではあまり重要な意味を持たない可能性があることを示唆している。To compare the in vitro pharmacological effect and in the brain distribution of benzodiazepines and phenobarbital, three group of sixty anesthetized rats (470～480g) were administered 5μCi of 3^H-diazepam, 3^H-flunitrazepam or 3^H-phenobarbital. The rats were decapitated 3, 10, or 40 minutes after the intravenous injection of these drugs. Radioactivity of the tissue was measured and calculated as d.p.m./g. tissue. 3^H-diazepam radioactivity in the brainstem and hypothalamus was significantly higher than in the brain cortex 3 and 10 minutes after the injection. 3^H-flunitrazepam radioactivity in the brain cortex was higher than in other regions. There was no significant decrease in 3^H-phenobarbital brain concentration, even 40 minutes after injection. The distribution of benzodiazepine is closely related with its pharmacological effect, and this suggests that in vitro benzodiazepine binding sites are not responsible for the pharmacological action in vivo

Tumor Necrosis Factor-alpha and Transforming Growth Factor-beta Synergistically Upregulate Endothelin-1 Expression in Human Bronchial Epithelial Cells BEAS-2B

Endothelin-1 is a peptide with many functions including bronchoconstriction and the stimulation of fibroblasts, and myofibroblasts, and airway smooth muscle cell proliferation. These functions are related to airway remodeling and endothelin-1 is known to be upregulated in the epithelium of patients with severe asthma. We thus sought to elucidate the mechanisms underlying endothelin-1 expression in bronchial epithelial cells in vitro. The human bronchial epithelial cell line BEAS-2B was grown in culture and then treated with tumor necrosis factor-alpha (TNF-α), interleukin-4 (IL-4), interleukin-13 (IL-13), and transforming growth factor-beta (TGF-β). Expression of endothelin-1 mRNA and protein was quantified by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. We also repressed expression of the key transcription factor in the pathogenesis of severe asthma, nuclear factor-kappa B (NF-κB), using small interfering RNA (siRNA). TNF-α and TGF-β significantly increased the release of endothelin-1 protein into the culture medium of BEAS-2B cells at 24 h after treatment compared to untreated cells; however, the Th2 cytokines, IL-4 and IL-13, had no effect. Endothelin-1 mRNA expression was also upregulated by TNF-α and TGF-β with a peak time point at 4 h after stimulation. Finally, the combination of TNF-α and TGF-β synergistically increased both endothelin-1 protein secretion and mRNA expression, and this upregulation was significantly suppressed in cells transfected with siRNA to repress NF-κB expression. TNF-α and TGF-β synergistically upregulate the expression of endothelin-1 in human bronchial epithelial cells, possibly via the activity of NF-κB. Our findings thus suggest NF-κBa as a potential therapeutic target for the regulation of airway remodeling

Expression of ICAM-1 on human bronchial epithelial cells after influenza virus infection

Damage of bronchial epithelium is a feature of airway viral infection and airway inflammatory disease, such as bronchial asthma. Adhesion molecules, which are expressed on bronchial epithelium, play an important role in the pathogenesis of epithelial damage and airway inflammation. We analysed ICAM-1 and VCAM-1 expression on human bronchial epithelial cell line, NCI-H292, after influenza virus A infection. ICAM-1 was expressed on control cells constitutively. Influenza virus A infection caused a three-fold increase in ICAM-1 expression on NCI-H292 cells. Supernatant of virus-infected cells was analysed for the concentration of IL-1β and TNF-α but these cytokines were not detected. VCAM-1 was not expressed on control cells and did not change after cytokine stimulation or virus infection. These findings suggest that influenza virus infection may induce ICAM-1 expression on bronchial epithelium without intervention of leukocytes, and ICAM-1 expressed on epithelium plays a major part in the pathophysiology of airway inflammatory disease caused by viral infection

Clarithromycin-resistant Mycobacterium Shinjukuense Lung Disease: Case Report and Literature Review

Mycobacterium shinjukuense is a species of non-tuberculous mycobacteria newly reported in 2010. Herein, we report on an 85-year-old woman with M. shinjukuense lung disease. Radiographic examinations showed consolidation with bronchiectasis, which responded transiently to clarithromycin monotherapy. After 1 year of monotherapy, the diagnosis was established and drug susceptibility testing revealed elevated minimum inhibitory concentration for clarithromycin. The patient was then treated successfully with a combination of antituberculosis drugs. The transient response to clarithromycin suggested that the M. shinjukuense had acquired resistance to clarithromycin. Appropriate treatment for M. shinjukuense lung disease has not yet been established; therefore, it is important to accumulate information from case reports

Comparison of Physicians’ Compliance, Clinical Efficacy, and Drug Cost before and after Introduction of Asthma Prevention and Management Guidelines in Japan (JGL2003)

Background: This study investigated the variations in the clinical efficacy and drug cost following the introduction of the Asthma Prevention and Management Guidelines in Japan (JGL2003). Methods: The medical charts of fifty outpatients treated continuously for asthma, aged 16-50 years, from October 2002 to October 2004 at Showa University Hospital were analyzed for physicians’ compliance with asthma guidelines, symptom severity, episodes in various occasions, prescriptions and drug costs. Results: Physicians’ compliance with the guidelines, which were defined as the number of patient visits treated in conformity with the JGL over the total number of patient visits, was found to be high before (89.4%) and after (90.3%) the introduction of JGL2003, without a statistical difference. On the other hand, the distribution of asthma symptom severity varied significantly (P < 0.0001). Fewer patients were recognized as having more severe asthma symptoms after the introduction of JGL2003. Significantly more patients with severe asthma symptoms were detected in the physicians’ noncompliant group than in the compliant group (P < 0.0001). The number of patients prescribed with oral corticosteroids, long-acting β2-agonists containing patches, long-acting oral β2-agonists, short-acting inhaled β2-agonists, sustained-released theophylline and leukotriene receptor antagonists decreased after the introduction of JGL2003. Furthermore, the total annual drug cost per patient decreased significantly by an average of 16,259 yen (P = 0.006). Conclusions: The JGL2003 was judged to have improved criteria, which thus resulted in the high compliance of physicians with the guidelines, in the remission of asthma symptoms and in the reduction in the total annual drug cost per patient

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