Kazutaka Takami

Tumor necrosis factor-α enhances both epithelial-mesenchymal transition and cell contraction induced in A549 human alveolar epithelial cells by transforming growth factor-β1

ABSTRACT Recently, epithelial-mesenchymal transition (EMT) has been reported to contribute to tissue fibrosis through enhanced transforming growth factor (TGF)-β1 signaling. Tumor necrosis factor (TNF)-α has also been implicated in tissue fibrosis. Therefore, the authors investigated whether TNF-α affected TGF-β1–induced EMT. Cultured alveolar epithelial cells (A549 cells) were stimulated with TGF-β1 (5 ng/mL), with/without TNF-α (10 ng/mL). TGF-β1 induced EMT of A549 cells, with loss of E-cadherin and acquisition of vimentin. Combination of TNF-α with TGF-β1 enhanced EMT, causing morphological changes, while quantitative polymerase chain reaction (PCR) showed suppression of E-cadherin mRNA and expression of vimentin mRNA. In addition, the gel contraction method revealed that cells that had undergone EMT acquired cell contractility, which is a feature of mesenchymal cells. Stimulation with TGF-β1 induced cell contraction, as did TNF-α. Moreover, costimulation with TGF-β1 and TNF-α enhanced the cell contraction. Although IFN-γ suppressed spontaneous cell contraction, it did not suppress cell contraction, which was induced by TGF-β1. In conclusion, TNF-α enhances not only EMT but also cell contraction induced by TGF-β1. EMT might contribute to tissue fibrosis through induction of cell contraction.

Simultaneous Stimulation with TGF-β1 and TNF-α Induces Epithelial Mesenchymal Transition in Bronchial Epithelial Cells

Background: Airway remodeling is an important feature of chronic airway disease, but the mechanisms involved remain unclear. Recently, epithelial mesenchymal transition (EMT) was reported to be associated with tissue fibrosis. TGF-β1, which is a potent inducer of EMT, is thought to be related to the pathogenesis of airway remodeling. We investigated whether TGF-β1 and/or TNF-α induce EMT in bronchial epithelial cells. Methods: Cultured BEAS-2B cells and primary normal human bronchial epithelial cells (NHBE) were treated with TGF-β1 and/or TNF-α. Morphological changes and the expression of EMT-related markers were evaluated by immunocytochemical staining. Expressions of EMT-related markers, extracellular matrix (ECM) components (collagen type I and versican), and TGF-β receptors I, II, and III were analyzed by quantitative RT-PCR. Migration was evaluated using the Boyden chamber technique. Results: The TGF-β1-induced EMT in BEAS-2B cells was demonstrated on the basis of morphological changes and the downregulation of E-cadherin. Costimulation with TNF-α enhanced the TGF-β1-induced morphological changes and increased vimentin expression. Treatment with TGF-β1 increased the expression of collagen type I and versican. EMT induced with TGF-β1 plus TNF-α promoted cell migration. Stimulation of NHBE with TGF-β1 led to EMT. Conclusion: TGF-β1 induced EMT in BEAS-2B cells, and costimulation with TNF-α enhanced the EMT. As a result of the EMT process, BEAS-2B cells acquired functions of mesenchymal cells. In addition, TGF-β1 treatment induced EMT in NHBE as shown by changes in EMT-related markers. Bronchial epithelial cells might contribute to airway remodeling through EMT.

Paradoxical association between body mass index and in-hospital mortality in elderly patients with chronic obstructive pulmonary disease in Japan

Background and objective The prevalence and mortality of chronic obstructive pulmonary disease (COPD) in elderly patients are increasing worldwide. Low body mass index (BMI) is a well-known prognostic factor for COPD. However, the obesity paradox in elderly patients with COPD has not been well elucidated. We investigated the association between BMI and in-hospital mortality in elderly COPD patients. Methods Using the Diagnosis Procedure Combination database in Japan, we retrospectively collected data for elderly patients (>65 years) with COPD who were hospitalized between July 2010 and March 2013. We performed multivariable logistic regression analysis to compare all-cause in-hospital mortality between patients with BMI of <18.5 kg/m2 (underweight), 18.5–22.9 kg/m2 (low–normal weight), 23.0–24.9 kg/m2 (high–normal weight), 25.0–29.9 kg/m2 (overweight), and ≥30.0 kg/m2 (obesity) with adjustment for patient backgrounds. Results In all, 263,940 eligible patients were identified. In-hospital mortality was 14.3%, 7.3%, 4.9%, 4.3%, and 4.4%, respectively, in underweight, low–normal weight, high–normal weight, overweight, and obese patients. Underweight patients had a significantly higher mortality than low–normal weight patients (odds ratio [OR]: 1.55, 95% confidence interval [CI]: 1.48–1.63), whereas lower mortality was associated with high–normal weight (OR: 0.76, CI: 0.70–0.82), overweight (OR: 0.73, CI: 0.66–0.80), and obesity (OR: 0.67, CI: 0.52–0.86). Higher mortality was significantly associated with older age, male sex, more severe dyspnea, lower level of consciousness, and lower activities of daily living. Conclusion Overweight and obese patients had a lower mortality than low–normal weight patients, which supports the obesity paradox.

Comparison of in-hospital mortality in patients with COPD, asthma and asthma-COPD overlap exacerbations.

Obstructive airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), have airflow limitation associated with chronic inflammation. Using a national inpatient database in Japan, we aimed to evaluate factors affecting in‐hospital mortality in patients with asthma, COPD or asthma–COPD overlap (ACO).

Clinical features of 280 hospitalized patients with lymphangioleiomyomatosis in Japan

Lymphangioleiomyomatosis (LAM) is rare, but potentially life threatening owing to respiratory failure. However, knowledge is limited about the condition of hospitalized LAM patients. The objectives of this study were to investigate patient characteristics, comorbidities and causes of death among hospitalized LAM patients in Japan.

C-reactive protein modulates human lung fibroblast migration.

C-reactive protein (CRP) has been classically used as a marker of inflammation. The aim of this study was to investigate the effect of CRP on migration of human fetal lung fibroblasts (HFL-1) to human plasma fibronectin (HFn). Using the blindwell chamber technique, CRP inhibited HFL-1 migration in a dose-dependent fashion (at 1 μ g/mL, inhibition: 32.5% ± 7.1%; P <.05). Western blot analysis showed that CRP inhibited the p38 mitogen-activated protein kinase (MAPK) activity in the presence of HFn. Moreover, the MAPK inhibitors SB202190 (25 μ M) and SB203580 (25 μ M) inhibited HFn-induced cell migration, suggesting an important role of p38 MAPK in HFn-induced migration. Taken together, these results suggest that the inhibitory effect of CRP is mediated by blocking MAPK. In summary, this study demonstrates that CRP directly modulates human lung fibroblasts migration. Thus, CRP may contribute to regulation of wound healing and may be endogenous antifibrotic factor acting on lung fibrosis.