Jiro Usuki

Epidemiology of sarcoidosis in Japan

The present study was designed to identify recent clinical phenotypes using the National Epidemiological Survey and to compare findings with those of previous surveys in Japan. Pathologically confirmed sarcoidosis cases newly diagnosed in 2004 were eligible for the present study. Disease parameters were recorded and compared. A total of 1,027 patients were enrolled from a cluster encompassing 79.4% of the entire Japanese population. The study participants consisted of 364 males and 663 females, providing an average incidence rate of 1.01 per 100,000 inhabitants (0.73 for males and 1.28 for females). The age-specific incidence rate displayed a biphasic pattern in the whole patient population and in the females. The male incidence rates peaked in the 20–34-yr-old group. A second peak for 50–60-yr-old females showed a higher incidence than the first younger peak. Patients with abnormalities in eyes, skin and cardiac laboratory findings accounted for 54.8, 35.4 and 23.0% of cases, respectively. The female/male incidence ratio was increased, and the frequency of eye and skin involvement and cardiac abnormality was higher than in previous surveys conducted in Japan. In conclusion, the data obtained in the present study differ from those of other countries and showed changes in sarcoidosis clinical phenotypes compared with previous studies in Japan.

Evolution of three patterns of intra‐alveolar fibrosis produced by bleomycin in rats

In pulmonary fibrosis, it is known that fibrotic changes develop in the intra‐alveolar spaces and that intra‐alveolar fibrosis can be classified into three patterns, namely intraalveolar buds, mural incorporation and obliterative changes. In order to clarify the evolution of intra‐alveolar fibrosis, immunohistochemical studies of extracellular matrix proteins and electron microscopic observations were made of the lungs of rats given a single intretracheal instillation of bleomycin. All three patterns of fibrosis developed in this model. Intra‐alveolar buds changed into globular lesions with dense collagen deposition, the surface of which was covered by alveolar epithelium. Electron microscopy revealed that the buds often contained spiraling collagen fibrils and numerous microfibrils, but not mature elastic fibres, beneath the regenerating epithelial lining cells; the epithelial basement membranes were discontinuous. In contrast, mural incorporation and obliterative changes ware associated with alveolar structural remodeling. Electron microscopically, these lesions had bundles of normal collagen fibrils, small elastic fibers, and continuous epithelial basement membranes. These results indicate that: (i) intra‐alveolar buds, that become intra‐alveolar collagen globules, with an unusual extracellular matrix, do not contribute to alveolar structural remodelling; and (ii) areas of mural incorporation and obliterative changes have the usual type of extracellular matrix and are essential for alveolar structural remodeling.

EM703 improves bleomycin-induced pulmonary fibrosis in mice by the inhibition of TGF-β signaling in lung fibroblasts

BackgroundFourteen-membered ring macrolides have been effective in reducing chronic airway inflammation and also preventing lung injury and fibrosis in bleomycin-challenged mice via anti-inflammatory effects. EM703 is a new derivative of erythromycin (EM) without the bactericidal effects. We investigated the anti-inflammatory and antifibrotic effects of EM703 in an experimental model of bleomycin-induced lung injury and subsequent fibrosis in mice.MethodsSeven-week-old male ICR mice were used. All experiments used eight mice/group, unless otherwise noted in the figure legends. Bleomycin was administered intravenously to the mice on day 0. EM703 was orally administered daily to mice. All groups were examined for cell populations in the bronchoalveolar lavage (BAL) fluid and for induction of messenger RNA (mRNA) of Smad3 and Smad4 in the lung tissues by reverse transcriptase (RT)-polymerase chainreaction (PCR) on day 7. Fibroblastic foci were assessed histologically, and the hydroxyproline content was chemically determined in the lung tissues on day 28. We performed assay of proliferation and soluble collagen production, and examined the induction of mRNA of Smad3 and Smad4 by RT-PCR in murine lung fibroblast cell line MLg2908. We also examined Smad3, Smad4 and phosphorylated Smad2/3 (p-Smad2/3) protein assay by western blotting in MLg2908.ResultsBleomycin-induced lung fibrosis, and the infiltration of macrophages and neutrophils into the airspace were inhibited by EM703. The expression of Smad3 and Smad4 mRNA was clearly attenuated by bleomycin, but was recovered by EM703. EM703 also inhibited fibroblast proliferation and the collagen production in lung fibroblasts induced by Transforming growth factor-beta (TGF-β). The expression of Smad3 and Smad4 mRNA in murine lung fibroblasts disappeared due to TGF-β, but was recovered by EM703. EM703 inhibited the expression of p-Smad2/3 and Smad4 protein in murine lung fibroblasts induced by TGF-β.ConclusionThese findings suggest that EM703 improves bleomycin-induced pulmonary fibrosis in mice by actions of anti-inflammation and regulation of TGF-β signaling in lung fibroblasts.

Differences in the clinical characteristics of Pneumocystis jirovecii pneumonia in immunocompromized patients with and without HIV infection

Background and objective:  The incidence of Pneumocystis jirovecii pneumonia (PCP) in patients with predisposing immunodeficiencies other than AIDS is growing. Knowing the different characteristics and outcomes of PCP according to HIV status would help physicians manage and treat patients with PCP.

Reduction in serum high mobility group box-1 level by polymyxin B-immobilized fiber column in patients with idiopathic pulmonary fibrosis with acute exacerbation.

Background/Aim: Recent reports suggest that polymyxin B (PMX)-immobilized fiber may have beneficial effects in idiopathic pulmonary fibrosis (IPF) with acute exacerbation (AE). High mobility group box-1 (HMGB-1) is an important pro-inflammatory mediator that contributes to acute lung inflammation. This study was aimed to investigate whether PMX treatment affects serum HMGB-1 levels and oxygenation in IPF patients with AE. Materials and Methods: Twenty IPF patients with AE were treated by PMX. PMX treatment was carried out once daily for 2 successive days. Serum HMGB-1 levels were measured before and after PMX treatment. We also monitored arterial oxygen tension (PaO2)/inspiratory oxygen fraction (FiO2) (P/F) ratio. PMX fiber columns were analyzed to examine whether HMGB-1 was absorbed by PMX. Results: PMX treatment significantly improved both the serum HMGB-1 level and P/F ratio. HMGB-1 was detected in washing medium from the PMX column. Conclusion: PMX treatment may reduce serum HMGB-1 and improve oxygenation in patients with IPF with AE.

Neutrophil Adsorption by Polymyxin B-Immobilized Fiber Column for Acute Exacerbation in Patients with Interstitial Pneumonia: A Pilot Study

Background/Aims: Polymyxin B-immobilized fiber (PMX) treatment has beneficial effects in patients with acute lung injury/acute respiratory distress syndrome or acute exacerbation of idiopathic pulmonary fibrosis. This study was aimed to clarify the mechanism of PMX treatment for acute exacerbation of interstitial pneumonia (IP). Materials and Methods: Sixteen consecutive IP patients with acute exacerbation were included. The patients were treated with PMX once daily for 2 successive days at a flow rate of 80–100 ml/min for 6 h. Cells adsorbed by PMX were analyzed morphologically by electron microscopy. Surface markers of these cells were determined by flow cytometry. Serum matrix metalloproteinase (MMP)-9 was measured before and after PMX treatment. Results: Cells adsorbed by PMX were neutrophils and highly expressed HLA-DR, CD14, CD62L and CD114. Serum MMP-9 levels were significantly decreased after PMX treatment. Conclusion: This pilot study demonstrated neutrophil adsorption by PMX and its possible clinical application for acute exacerbation of IP.

EM703, A NEW DERIVATIVE OF ERYTHROMYCIN, INHIBITS TRANSFORMING GRWTH FACTOR-β SIGNALING IN HUMAN LUNG FIBROBLASTS

Long-term, low-dose macrolide therapy has been proven to improve survival in patients with diffuse panbronchiolitis and cystic fibrosis, although the mechanisms by which it does so remain unknown. To elucidate the molecular mechanisms of the anti-inflammatory effects of macrolides, the authors examined the effects of erythromycin (EM-A) and new derivative EM703 on transforming growth factor (TGF)-β /Smad signaling fibroblasts. EM-A and EM703 each inhibited fibroblast proliferation and the collagen production in human lung fibroblasts induced by TGF-β. EM-A and EM703 inhibited the augmentation of Smad3 mRNA induced by TGF-β. Smad7 mRNA was inhibited by TGF-β, but augmented by coincubation with EM-A or EM703. EM-A and EM703 each inhibited p-Smad2/3 proteins induced by TGF-β. Smad7 protein inhibited by TGF-β restored beyond basal level by EM-A and EM703. These findings suggest that EM-A and EM703 inhibit TGF-β signaling in human lung fibroblasts via inhibition of p-Smad2/3 through recovery of Smad7 level.

Nintedanib modulates surfactant protein-D expression in A549 human lung epithelial cells via the c-Jun N-terminal kinase-activator protein-1 pathway.

Idiopathic pulmonary fibrosis (IPF) is a progressive disease with a high mortality rate. Signalling pathways activated by several tyrosine kinase receptors are known to be involved in lung fibrosis, and this knowledge has led to the development of the triple tyrosine kinase inhibitor nintedanib, an inhibitor of vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and fibroblast growth factor receptor (FGFR), for the treatment of IPF. Pulmonary surfactant protein D (SP-D), an important biomarker of IPF, reportedly attenuates bleomycin-induced pulmonary fibrosis in mice. In this study, we investigated whether nintedanib modulates SP-D expression in human lung epithelial (A549) cells using quantitative real-time reverse transcriptase polymerase chain reaction and western blotting. To investigate the mechanisms underlying the effects of nintedanib, we evaluated the phosphorylation of c-Jun N-terminal kinase (JNK) and its downstream target c-Jun. The effect of the JNK inhibitor SP600125 on c-Jun phosphorylation was also tested. Activation of activator protein-1 (AP-1) was examined using an enzyme-linked immunosorbent assay-based test, and cell proliferation assays were performed to estimate the effect of nintedanib on cell proliferation. Furthermore, we treated mice with nintedanib to examine its in vivo effect on SP-D levels in lungs. These experiments showed that nintedanib up-regulated SP-D messenger RNA expression in a dose-dependent manner at concentrations up to 5 μM, with significant SP-D induction observed at concentrations of 3 μM and 5 μM, in comparison with that observed in vehicle controls. Nintedanib stimulated a rapid increase in phosphorylated JNK in A549 cells within 30 min of treatment and stimulated c-Jun phosphorylation, which was inhibited by the JNK inhibitor SP600125. Additionally, nintedanib was found to activate AP-1. A549 cell proliferation was not affected by nintedanib at any of the tested concentrations. Moreover, blocking FGFR, PDGFR, and VEGFR function did not affect nintedanib-induced SP-D expression, suggesting that nintedanib mediates its effects through a mechanism that is distinct from its known role as a tyrosine kinase inhibitor. Nintedanib is also reported to inhibit Src kinase although pre-treatment of cells with a Src kinase inhibitor had no effect on nintedanib-induced SP-D expression. Increased expression of SFTPD mRNA and SP-D protein in the lungs of nintedanib-treated mice was also observed. In this work, we demonstrated that nintedanib up-regulated SP-D expression in A549 cells via the JNK-AP-1 pathway and did not affect cell proliferation. This is the first report describing SP-D induction by nintedanib.