Tomoyuki Fujisawa

Regulation of Airway MUC5AC Expression by IL-1β and IL-17A; the NF-κB Paradigm

Mucin over-production is one of the hallmarks of chronic airway diseases such as chronic obstructive pulmonary disease, asthma, and cystic fibrosis. NF-κB activation in airway epithelial cells has been shown to play a positive inflammatory role in chronic airway diseases; however, the role of NF-κB in mucin gene expression is unresolved. In this study, we have shown that the proinflammatory cytokines, IL-1β and IL-17A, both of which utilize the NF-κB pathway, are potent inducers of mucin (MUC)5AC mRNA and protein synthesis by both well-differentiated primary normal human bronchial epithelial cells and the human bronchial epithelial cell line, HBE1. MUC5AC induction by these cytokines was both time- and dose-dependent and occurred at the level of promoter activation, as measured by a reporter gene assay. These effects were attenuated by the small molecule inhibitor NF-κB inhibitor III, as well as p65 small-interfering RNA, suggesting that the regulation of MUC5AC expression by these cytokines is via an NF-κB-based transcriptional mechanism. Further investigation of the promoter region identified a putative NF-κB binding site at position-3594/-3582 in the promoter of MUC5AC as critical for the regulation of MUC5AC expression by both IL-1β and IL-17A. Chromatin immunoprecipitation analysis confirmed enhanced binding of the NF-κB subunit p50 to this region following cytokine stimulation. We conclude that an NF-κB-based transcriptional mechanism is involved in MUC5AC regulation by IL-1β and IL-17A in the airway epithelium. This is the first demonstration of the participation of NF-κB and its specific binding site in cytokine-mediated airway MUC5AC expression.

Cumulative incidence of and predictive factors for lung cancer in IPF.

Background and objective:  Previous studies have indicated a high incidence of lung cancer in IPF, and some have identified its risk factors. However, those studies were retrospective and the clinical characteristics of IPF patients developing lung cancer were evaluated only when those patients had developed the cancer. The true cumulative incidence of lung cancer after the diagnosis of IPF and its predictive factors at the initial diagnosis of IPF remain unknown. The present study was conducted to elucidate the cumulative incidence and risk factors for lung cancer in IPF patients by retrospective longitudinal cohort analysis.

Interstitial lung diseases associated with amyopathic dermatomyositis

The aim of the present study was to clarify the clinical characteristics and prognosis of patients with interstitial lung disease (ILD) associated with amyopathic dermatomyositis (ILD-ADM). The study consisted of 14 consecutive patients with ILD-ADM. Patients were classified into two categories, acute/subacute and chronic forms, according to the clinical presentation of ILD. The clinical features, responsiveness to therapy, and prognosis between the two forms were compared. Nine ILD-ADM patients were categorised as the acute/subacute form, and five as the chronic form. Arterial oxygen tension was significantly lower in the acute/subacute ILD than chronic ILD patients. On high-resolution computed tomography, ground-glass opacities were frequently found in the two forms, but consolidation was more common in acute/subacute ILD than chronic ILD. Bronchoalveolar lavage analysis showed higher numbers of total cells and lymphocytes in acute/subacute ILD than chronic ILD. Histologically, the most common finding was nonspecific interstitial pneumonia in the two forms, while diffuse alveolar damage was only found in acute/subacute ILD. Acute/subacute ILD was generally resistant to therapy, while chronic ILD responded well. Notably, the mortality of acute/subacute ILD was much higher than that of chronic ILD (67 versus 0%, respectively). In conclusion, interstitial lung disease associated with amyopathic dermatomyositis includes two different forms, the acute/subacute and chronic forms, with distinct prognoses.

Mouse Lung CD103+ and CD11bhigh Dendritic Cells Preferentially Induce Distinct CD4+ T-Cell Responses

Mouse lung dendritic cells (LDCs) have been recently shown to contain two major subpopulations: CD103(+) CD11b(low or negative) (CD103(+) LDCs) and CD103(-) CD11b(high) LDCs (CD11b(high) LDCs). Although several studies have demonstrated functional differences between them, it is unclear whether the subpopulations induce distinct T helper (Th) cell responses. The present study was conducted to examine whether CD103(+) and CD11b(high) LDCs preferentially generate different Th responses. Naive DO11.10 CD4(+) T cells were primed with CD103(+) or CD11b(high) LDCs obtained from normal BALB/c mice. The primed CD4(+) T cells were restimulated, and their cytokine secretions were assessed. The expression of intracellular cytokines and the mRNA levels of chemokine receptors were also measured. We found that the CD4(+) T cells primed with CD103(+) LDCs secreted significantly larger amounts of IFN-γ and IL-17A, whereas those primed with CD11b(high) LDCs released significantly higher levels of IL-4, IL-6, and IL-10. Intracellular cytokine assay showed that CD103(+) LDCs induced greater frequencies of CD4(+) T cells producing IFN-γ and IL-17A, whereas CD11b(high) LDCs were more efficient at inducing CD4(+) T cells producing IL-4 and IL-10. The mRNA levels of CXCR3 and CCR5, which are expressed preferentially in Th1 cells, were significantly higher in CD4(+) T cells primed with CD103(+) LDCs. The mRNA levels of CXCR4 and CCR4, which are expressed primarily in Th2 cells, were significantly greater in those primed with CD11b(high) LDCs. These data suggest that mouse CD103(+) LDCs predominantly elicit Th1 and Th17 responses, whereas CD11b(high) LDCs primarily provoke a Th2 response under the steady state.

Idiopathic pleuroparenchymal fibroelastosis: consideration of a clinicopathological entity in a series of Japanese patients

BackgroundIdiopathic pleuroparenchymal fibroelastosis (IPPFE) is a recently reported group of disorders characterized by fibrotic thickening of the pleural and subpleural parenchyma predominantly in the upper lobes. We report five Japanese cases fulfilling the criteria of IPPFE and address whether it should be considered a separate clinicopathologic entity. And this study was an attempt to identify features in common between IPPFE and previously described idiopathic upper lobe fibrosis (IPUF), allowing IPPFE to be considered as a distinct entity in our Japanese series.MethodsFive consecutive cases of idiopathic interstitial lung disease confirmed as IPPFE by surgical lung biopsy were studied.ResultsThere were four males and one female, aged 70±2.76 yr. No associated disorder or presumed cause was found in any case. Lung function tests found a restrictive ventilatory defect (4/5) and/or impairment of DLco (4/5). Chest X-ray showed marked apical pleural thickening in all cases. Computed tomography of the chest in all cases mainly showed intense pleural thickening and volume loss associated with evidence of fibrosis, predominantly in the upper lobes. In all cases in this study, markedly thickened visceral pleura and prominent subpleural fibrosis characterized by both elastic tissue and dense collagen were clearly shown. All cases were alive at the last follow-up, 17.6±13.59 months after diagnosis; however, all had deteriorated both clinically and radiologically.ConclusionsIPPFE deserves to be defined as a separate, original clinicopathologic entity owing to its uniformity and IPPFE has some features in common with previously described idiopathic upper lobe fibrosis (IPUF). Our limited experience with a cohort of 5 subjects suggests that IPPFE can be rapidly progressive.

NF-κB Mediates IL-1β– and IL-17A–Induced MUC5B Expression in Airway Epithelial Cells

A major pathological feature of chronic airway diseases is the elevated expression of gel-forming mucins. NF-κB activation in airway epithelial cells has been shown to play a proinflammatory role in chronic airway diseases; however, the specific role of NF-κB in mucin gene expression has not been characterized. In this study, we show that the proinflammatory cytokines, IL-1β and IL-17A, both of which use the NF-κB pathway, are potent inducers of MUC5B mRNA expression in both well differentiated primary normal human bronchial epithelial cells and the human bronchial epithelial cell line, HBE1. MUC5B induction by these cytokines was both time- and dose-dependent, and was attenuated by the small molecule inhibitor, NF-κB inhibitor III, as well as p65 small interfering RNA, suggesting that the regulation of MUC5B expression by these cytokines is via an NF-κB-based transcriptional mechanism. Deletion analysis of the MUC5B promoter demonstrated that IL-1β- and IL-17A-induced promoter activity resides within the -4.17-kb to -2.56-kb region relative to the transcriptional start site. This region contains three putative κB-binding sites (NF-κB-1, -3,786/-3,774; NF-κB-2, -3,173/-3,161; and NF-κB-3, -2,921/-2,909). Chromatin immunoprecipitation analysis confirmed enhanced binding of the p50 NF-κB subunit to the NF-κB-3 site after cytokine stimulation. We conclude that an NF-κB-based transcriptional mechanism is involved in MUC5B regulation by IL-1β and IL-17A in airway epithelium. This is the first demonstration of the participation of NF-κB and its specific binding site in cytokine-mediated airway MUC5B expression.

Real‐time PCR is more specific than conventional PCR for induced sputum diagnosis of Pneumocystis pneumonia in immunocompromised patients without HIV infection

Background and objective:  The diagnosis of Pneumocystis pneumonia (PCP) is based on microscopic examination of respiratory specimens. PCP patients without AIDS have a lower burden of P. jiroveci than those with AIDS, which leads to difficulty in detecting the organisms. Although conventional PCR (c‐PCR) has been used to detect the DNA, it is frequently positive in patients with colonization. Real‐time PCR (r‐PCR), a method to detect the DNA quantitatively, might be helpful in distinguishing between infection and colonization. We investigated the utility of real‐time PCR in the diagnosis of PCP in non‐AIDS patients.

Prognostic Factors for Myositis-Associated Interstitial Lung Disease

Background Interstitial lung disease (ILD) is a common manifestation of polymyositis (PM), dermatomyositis (DM), and clinically amyopathic dermatomyositis (CADM); however, little is known about the factors influencing the prognosis for PM/DM/CADM-associated ILD. (PM/DM/CADM-ILD). The aim of the present study is to assess prognostic factors for PM/DM/CADM-ILD. Methods The clinical features and survival of 114 consecutive patients diagnosed with PM/DM/CADM-ILD (39 men and 75 women; median age, 56 years) were analyzed retrospectively. Results The study group included 30 PM-associated ILD, 41 DM-associated ILD, and 43 CADM-associated ILD cases. The clinical presentation of ILD was acute/subacute form in 59 patients (51.8%) and chronic form in 55 patients (48.2%). The major pulmonary symptoms were dyspnea, cough, and fever. High-resolution computed tomography frequently revealed ground-glass opacities, traction bronchiectasis, and consolidation. Most of the patients were treated with corticosteroids or corticosteroids in combination with immunosuppressive agents. The all-cause mortality was 27.2%. Acute/subacute form, % forced vital capacity (FVC), age, % of neutrophils in bronchoalveolar lavage (BAL) fluid, and a diagnosis of CADM (vs. PM) were significantly associated with poor outcome in univariate Cox proportional hazards models. Multivariate Cox proportional hazards analysis validated acute/subacute ILD, %FVC, age, and diagnosis of CADM (vs. PM) as significant predictors of overall mortality. Patients with acute/subacute ILD had a much lower survival rate than those with the chronic form (p<0.001). Patients with CADM-ILD had a lower survival rate than those with PM-ILD (p = 0.034). Conclusions Acute/subacute form, older age, lower level of FVC and diagnosis of CADM predict poor outcome in PM/DM/CADM-ILD.

Rheumatoid lung disease: Prognostic analysis of 54 biopsy-proven cases

OBJECTIVE To investigate the prognostic significance of histopathological characteristics in patients with biopsy-proven rheumatoid lung disease (RLD). MATERIALS AND METHODS Retrospective analysis was conducted on samples from 54 RLD patients who underwent surgical lung biopsies (SLBs) at Hamamatsu University Hospital and affiliated hospitals between 1980 and 2009. The overall survival rate, the spectrum of histopathological diagnosis and their associated prognostic significance were investigated. RESULTS The study group consisted of 30 men and 24 women with a median age of 60.3 years. Histopathological analysis revealed the following: usual interstitial pneumonia (UIP), 15 cases; nonspecific interstitial pneumonia/fibrosis, 16 cases; organizing pneumonia, 4 cases; unclassifiable, 2 cases; desquamative interstitial pneumonia, 1 case; and bronchiolar disease, 16 cases. In survival outcome, 10 yr survival rate was 76.6%. Patients with UIP had significantly worse prognosis than those with non-UIP (RLD cases except those with UIP) (p = 0.0452). CONCLUSION RLD includes several histopathological groups. Patients with UIP have worse survival than those with other types of RLD. Histopathological diagnosis may have a major impact on prognostication in patients with RLD.

Possible therapeutic effect of direct haemoperfusion with a polymyxin B immobilized fibre column (PMX-DHP) on pulmonary oxygenation in acute exacerbations of interstitial pneumonia.

Background and objective:  Acute exacerbations of interstitial pneumonias (IP) can occasionally occur, and have an extremely poor prognosis. Recently, direct haemoperfusion with a polymyxin B immobilized fibre column (PMX‐DHP) was shown to have a beneficial effect in acute exacerbations of IPF. However, little is known about the efficacy of PMX‐DHP in acute exacerbations of other IP. This study investigated the effectiveness and safety of PMX‐DHP in acute exacerbations of IP.