Cardiac angiosarcoma with metastatic to lung, brain, and bone

Cardiac angiosarcoma is a malignant tumor derived from vascular endothelium with a dismal prognosis. The imaging findings of cardiac angiosarcoma are nonspecific and endomyocardial and pericardial biopsies have insufficient accuracy. For these reasons, the diagnosis is sometimes difficult. Primary and metastatic tumors tend to bleed easily, causing hemoptysis and neurological symptoms. Brain metastases are not often known to be fatal when they cause hemorrhage. We report a 27-year-old man diagnosed with right atrium angiosarcoma, with metastases in the lung, brain, and bone. The patient had only respiratory symptoms at the first visit and did not show any symptoms derived from brain metastases yet died after 27 days due to hemorrhage from brain metastases. If brain metastasis from angiosarcoma is suspected based on imaging findings, urgent radiotherapy should be considered before histological examination for a definitive diagnosis.

Questionnaire for diagnosing asthma-COPD overlap in COPD: Development of ACO screening questionnaire (ACO-Q)

BACKGROUND

The considerable prevalence and worse outcomes of asthma-COPD overlap (ACO) in COPD have been reported, and optimal introduction of ICS is essential for ACO. However, diagnostic criteria for ACO consist of multiple laboratory tests, which is challenging during this COVID-19 era. The purpose of this study was to create a simple questionnaire to diagnose ACO in patients with COPD.

METHODS

Among 100 COPD patients, 53 were diagnosed with ACO based on the Japanese Respiratory Society Guidelines for ACO. Firstly, 10 candidate questionnaire items were generated and further selected by a logistic regression model. An integer-based scoring system was generated based on the scaled estimates of items.

RESULTS

Five items, namely a history of asthma, wheezing, dyspnea at rest, nocturnal awakening, and weather- or season-dependent symptoms, contributed significantly to the diagnosis of ACO in COPD. History of asthma was related to FeNO >35 ppb. Two points were assigned to history of asthma and 1 point to other items in the ACO screening questionnaire (ACO-Q), and the area under the receiver operating characteristic curve was 0.883 (95% CI: 0.806-0.933). The best cutoff point was 1 point, and the positive predictive value was 100% at a cutoff of 3 points or higher. The result was reproducible in the validation cohort of 53 patients with COPD.

CONCLUSIONS

A simple questionnaire, ACO-Q, was developed. Patients with scores ≥3 could be reasonably recommended to be treated as ACO, and additional laboratory testing would be recommended for patients with 1 and 2 points.

A phase II study of S-1 and cisplatin with concurrent thoracic radiotherapy followed by durvalumab for unresectable, locally advanced non-small-cell lung cancer in Japan (SAMURAI study): primary analysis

Background

The standard of care for unresectable, locally advanced non-small-cell lung cancer (LA-NSCLC) is chemoradiotherapy (CRT) followed by durvalumab, based on the PACIFIC study. Although multiple Japanese phase II studies have shown high efficacy and tolerability of CRT with cisplatin plus S-1 (SP), no prospective study using durvalumab after SP-based CRT has been reported.

Objectives

We conducted a multicenter phase II study of this approach, the interim analysis of which showed a high transition rate to durvalumab consolidation therapy. Here, we report the primary analysis results.

Design

In treatment-naïve LA-NSCLC, cisplatin (60 mg/m², day 1) and S-1 (80-120 mg/body, days 1-14) were administered with two 4-week cycles with concurrent thoracic radiotherapy (60 Gy) followed by durvalumab (10 mg/kg) every 2 weeks for up to 1 year.

Methods

The primary endpoint was 1-year progression-free survival (PFS). The expected 1-year PFS and its lower limit of the 80% confidence interval (CI) were set as 63% and 47%, respectively, based on the results of TORG1018 study.

Results

In all, 59 patients were enrolled, with 51 (86.4%) proceeding to durvalumab. The objective response rate throughout the study was 72.9% (95% CI: 59.7-83.6%). After median follow-up of 21.9 months, neither median PFS nor OS was reached. The 1-year PFS was 72.5% (80% CI: 64.2-79.2%, 95% CI: 59.1-82.2%), while the 1-year overall survival was 91.5% (95% CI: 80.8-96.4%). No grade 5 adverse events were observed throughout the study. The most common adverse event during the consolidation phase was pneumonitis (any grade, 78.4%; grade ⩾3, 2.0%). Eventually, 52.5% of patients completed 1-year durvalumab consolidation therapy from CRT initiation.

Conclusion

This study of durvalumab after SP-based CRT met its primary endpoint and found a 1-year PFS of 73% from CRT initiation. This study provides the first prospective data on the prognosis and tolerability of durvalumab consolidation from the initiation of CRT.

Trial registration

Japan Registry of Clinical Trials, jRCTs031190127, registered 1 November, 2019, https://jrct.niph.go.jp/latest-detail/jRCTs031190127.

Prospective analysis of factors precluding the initiation of durvalumab from an interim analysis of a phase II trial of S-1 and cisplatin with concurrent thoracic radiotherapy followed by durvalumab for unresectable, locally advanced non-small cell lung cancer in Japan (SAMURAI study)

Background:

The standard of care for unresectable, locally advanced non-small cell lung cancer (LA-NSCLC) is chemoradiotherapy (CRT) followed by durvalumab, based on the PACIFIC trial. Disease progression and pneumonitis were reported as the main reasons to preclude the initiation of durvalumab in multiple retrospective studies. However, the transition rate and the reasons for failure to proceed to consolidation therapy with durvalumab after CRT were not evaluated prospectively. Although phase II studies in Japan have shown high efficacy and tolerability of CRT with cisplatin + S-1 (SP), no prospective study using durvalumab after SP-based CRT has yet been reported. We therefore conducted a phase II study to verify the efficacy and safety of durvalumab following SP-based CRT. In this interim analysis, we report the transition rate and the reasons for its failure.

Methods:

In treatment-naïve LA-NSCLC, cisplatin (60 mg/m², day 1) and S-1 (80–120 mg/body, days 1–14) were administered with two 4-week cycles with concurrent thoracic radiotherapy (60 Gy) followed by durvalumab every 2 weeks for up to 12 months. The primary endpoint was 12 month progression-free survival rate.

Results:

Fifty-nine patients were enrolled, of whom 86.4% (51/59) proceeded to durvalumab. All of them initiated durvalumab within 42 days after CRT [median 18 days (range: 3–38)], including 27.5% (14/51) in <14 days. Common reasons for failure to proceed to durvalumab were disease progression (2/59, 3.4%) and adverse events (6/59, 10.2%). Among the latter cases, four resumed treatment and proceeded to durvalumab within 42 days on off-protocol. The objective response rate and the disease control rate were 62.7% and 93.2%, respectively. The incidences of ⩾grade 3 pneumonitis, febrile neutropenia, and esophagitis were 0%, 8.5%, and 3.4%, respectively.

Conclusion:

Regarding durvalumab after CRT, this interim analysis of the SAMURAI study clarified the high transition rate, early introduction, and reasons for failure to proceed to consolidation therapy, which were not determined in the PACIFIC trial.

Trial registration:

Japan Registry of Clinical Trials, jRCTs031190127, registered 1 November, 2019, https://jrct.niph.go.jp/latest-detail/jRCTs031190127.

A phase II study of S-1 and cisplatin with concurrent thoracic radiotherapy followed by durvalumab for unresectable, locally advanced non-small-cell lung cancer in Japan (SAMURAI study)

Background:

Based on the results of the PACIFIC study, chemoradiotherapy followed by 1-year consolidation therapy with durvalumab was established as the standard of care for unresectable, locally advanced non-small-cell lung cancer (LA-NSCLC). However, some topics not foreseen in that design can be explored, including progression-free survival (PFS) and overall survival (OS) after the start of chemoradiotherapy, the proportion of patients who proceeded to consolidation therapy with durvalumab, and the optimal chemotherapeutic regimens. In Japan, the combination regimen of S-1 + cisplatin (SP), for which the results of multiple clinical studies have suggested a good balance of efficacy and tolerability, is frequently selected in clinical settings. However, the efficacy and safety of consolidation therapy with durvalumab following this SP regimen have not been evaluated. We therefore planned a multicenter, prospective, single-arm, phase II study.

Methods:

In treatment-naïve LA-NSCLC, two cycles of combination chemotherapy with S-1 (80–120 mg/body, Days 1–14) + cisplatin (60 mg/m², Day 1) will be administered at an interval of 4 weeks, with concurrent thoracic radiotherapy (60 Gy). Responders will then receive durvalumab every 2 weeks for up to 1 year. The primary endpoint is 1-year PFS rate.

Discussion:

Compared with the conventional standard regimen in Japan, the SP regimen is expected to be associated with lower incidences of pneumonitis, esophagitis, and febrile neutropenia, which complicate the initiation of consolidation therapy with durvalumab, and have higher antitumor efficacy during chemoradiotherapy. Therefore, SP-based chemoradiotherapy is expected to be successfully followed by consolidation therapy with durvalumab in more patients, resulting in prolonged PFS and OS. Toxicity and efficacy results of the SP regimen in this study will also provide information important to the future establishment of the concurrent combination of chemoradiotherapy and durvalumab.

Trial registration:

Japan Registry of Clinical Trials, jRCTs031190127, registered 1 November 2019, https://jrct.niph.go.jp/latest-detail/jRCTs031190127

Pulmonary Apical Opacities on Thin-Section Computed Tomography: Relationship to Primary Spontaneous Pneumothorax in Young Male Patients and Corresponding Histopathologic Findings

OBJECTIVE

The purpose of this study was to test the hypothesis that apical opacities on computed tomography (CT) are related to occurrence of primary spontaneous pneumothorax (PSP) in young male patients.

METHODS

We compared the frequency of apical opacities on thin-section CT between 70 male patients with PSP (PSP group) and 74 male patients without a history of PSP (non-PSP group). We also evaluated histopathologic findings of 39 specimens from 37 surgical cases in the PSP group.

RESULTS

Apical opacities were significantly more frequent in the PSP group than in the non-PSP group (right side, P = 0.01; left side, P = 0.005). Histopathologically, subpleural band-like alveolar collapse was seen in 35 specimens (89.7%), which was always accompanied by fibroelastosis and fibroblastic foci.

CONCLUSIONS

Apical opacities on CT were significantly associated with PSP in young male patients. These apical opacities histopathologically correspond to fibrotic pleural thickening with subpleural alveolar collapse.

Hemoglobin Kansas as a Rare Cause of Cyanosis: A Case Report and Review of the Literature

Hemoglobin (Hb) Kansas is an inherited Hb variant with a low oxygen affinity that is associated with low oxygen saturation on pulse oximetry (SpO₂). It leads to asymptomatic cyanosis. Patients with Hb Kansas do not require any specific treatment and the prognosis is good. In patients with unexplained cyanosis, we should thus consider Hb variants, including Hb Kansas and avoid unnecessary investigations and managements. We herein report the case of 65-year-old woman with Hb Kansas and review five other cases (three lineages) that have been reported in Japan.

Serum Reactive Oxygen Metabolite Levels Predict Severe Exacerbations of Asthma

Background and Purpose

Bronchial asthma (BA) is a chronic airway disease characterized by airway hyperresponsiveness and remodeling, which are intimately linked to chronic airway inflammation. Reactive oxygen species (ROS) such as hydrogen peroxide are generated by inflammatory cells that are involved in the pathogenesis of BA. However, the role of ROS in the management of BA patients is not yet clear. We attempted to determine the role of ROS as a biomarker in the clinical setting of BA.

Subjects and Methods

We enrolled patients with BA from 2013 through 2015 and studied the degrees of asthma control, anti-asthma treatment, pulmonary function test results, fractional exhaled nitric oxide (FeNO), serum reactive oxygen metabolite (ROM) levels, and serum levels of interleukin (IL)-6 and IL-8.

Results

We recruited 110 patients with BA. Serum ROM levels correlated with white blood cell (WBC) count (rs = 0.273, p = 0.004), neutrophil count (rs = 0.235, p = 0.014), CRP (rs = 0.403, p < 0.001), and IL-6 (rs = 0.339, p < 0.001). Serum ROM levels and IL-8 and CRP levels negatively correlated with %FEV₁ (rs = -0.240, p = 0.012, rs = -0.362, p < 0.001, rs = -0.197, p = 0.039, respectively). Serum ROM levels were significantly higher in patients who experienced severe exacerbation within 3 months than in patients who did not (339 [302–381] vs. 376 [352–414] CARR U, p < 0.025). Receiver-operating characteristics analysis showed that ROM levels correlated significantly with the occurrence of severe exacerbation (area under the curve: 0.699, 95% CI: 0.597–0.801, p = 0.025).

Conclusions

Serum levels of ROM were significantly associated with the degrees of airway obstruction, WBC counts, neutrophil counts, IL-6, and severe exacerbations. This biomarker may be useful in predicting severe exacerbations of BA.

Interleukin-17A and Toll-Like Receptor 3 Ligand Poly(I:C) Synergistically Induced Neutrophil Chemoattractant Production by Bronchial Epithelial Cells

Chronic inflammatory airway diseases, such as bronchial asthma and chronic obstructive pulmonary disease, are common respiratory disorders worldwide. Exacerbations of these diseases are frequent and worsen patients’ respiratory condition and overall health. However, the mechanisms of exacerbation have not been fully elucidated. Recently, it was reported that interleukin (IL)-17A might play an important role in neutrophilic inflammation, which is characteristic of such exacerbations, through increased production of neutrophil chemoattractants. Therefore, we hypothesized that IL-17A was involved in the pathogenesis of acute exacerbation, due to viral infection in chronic inflammatory airway diseases. In this study, we assessed chemokine production by bronchial epithelial cells and investigated the underlying mechanisms. Comprehensive chemokine analysis showed that, compared with poly(I:C) alone, co-stimulation of BEAS-2B cells with IL-17A and poly(I:C) strongly induced production of such neutrophil chemoattractants as CXC chemokine ligand (CXCL)8, growth-related oncogene (GRO), and CXCL1. Co-stimulation synergistically induced CXCL8 and CXCL1 mRNA and protein production by BEAS-2B cells and normal human bronchial epithelial cells. Poly(I:C) induced chemokine expression by BEAS-2B cells mainly via Toll-like receptor 3/TIR-domain-containing adapter-inducing interferon-β–mediated signals. The co-stimulation with IL-17A and poly(I:C) markedly activated the p38 and extracellular-signal-regulated kinase 1/2 pathway, compared with poly(I:C), although there was little change in nuclear factor-κB translocation into the nucleus or the transcriptional activities of nuclear factor-κB and activator protein 1. IL-17A promoted stabilization of CXCL8 mRNA in BEAS-2B cells treated with poly(I:C). In conclusion, IL-17A appears to be involved in the pathogenesis of chronic inflammatory airway disease exacerbation, due to viral infection by promoting release of neutrophil chemoattractants from bronchial epithelial cells.

Histamine induces human lung fibroblast-mediated collagen gel contraction via histamine H1 receptor

BACKGROUND

Airway remodeling is implicated in irreversible airflow limitation of refractory asthma, which includes increased smooth muscle mass and subepithelial fibrosis. Activated fibroblasts acquire contractile phenotype to participate in tissue contraction and structural alteration of extracellular matrices. Histamine is a potent mediator of allergic inflammation, substantially involved in asthmatic pathophysiology.

OBJECTIVE

We hypothesized that histamine might play a role in airway remodeling, and investigated its effect on fibroblast-mediated collagen gel contraction.

METHODS

Fibroblast-mediated collagen gel contraction was studied. Histamine's regulation of collagen gel contraction was characterized by using specific histamine-receptor antagonists, an IP3 receptor antagonist and a PKC inhibitor.

RESULTS

Histamine induced contraction of collagen gels embedded with human lung fibroblasts, in a time-dependent manner, and at the concentration more than 10(-6) M, both in four primary cultured adult lung fibroblasts and three fetal lung fibroblast cell lines. This effect was attenuated by H1 receptor antagonist, whereas those for H2 to H4 receptors failed to show an inhibitory effect. Furthermore, IP3 receptor-mediated Ca(2+) mobilization was implicated in histamine's action on collagen gel contraction.

CONCLUSIONS

Our results suggest that histamine is involved in airway remodeling through its action on lung fibroblasts, and antihistamine drugs, especially H1 receptor antagonists, might be potentially beneficial for a subset of asthmatic patients.

Lymphotoxin β receptor signaling induces IL-8 production in human bronchial epithelial cells

Asthma-related mortality has been decreasing due to inhaled corticosteroid use, but severe asthma remains a major clinical problem. One characteristic of severe asthma is resistance to steroid therapy, which is related to neutrophilic inflammation. Recently, the tumor necrosis factor superfamily member (TNFSF) 14/LIGHT has been recognized as a key mediator in severe asthmatic airway inflammation. However, the profiles and intracellular mechanisms of cytokine/chemokine production induced in cells by LIGHT are poorly understood. We aimed to elucidate the molecular mechanism of LIGHT-induced cytokine/chemokine production by bronchial epithelial cells. Human bronchial epithelial cells express lymphotoxin β receptor (LTβR), but not herpesvirus entry mediator, which are receptors for LIGHT. LIGHT induced various cytokines/chemokines, such as interleukin (IL)-6, oncostatin M, monocyte chemotactic protein-1, growth-regulated protein α and IL-8. Specific siRNA for LTβR attenuated IL-6 and IL-8 production by BEAS-2B and normal human bronchial epithelial cells. LIGHT activated intracellular signaling, such as mitogen-activated protein kinase and nuclear factor-κB (NF-κB) signaling. LIGHT also induced luciferase activity of NF-κB response element, but not of activator protein-1 or serum response element. Specific inhibitors of phosphorylation of extracellular signal-regulated kinase (Erk) and that of inhibitor κB attenuated IL-8 production, suggesting that LIGHT-LTβR signaling induces IL-8 production via the Erk and NF-κB pathways. LIGHT, via LTβR signaling, may contribute to exacerbation of airway neutrophilic inflammation through cytokine and chemokine production by bronchial epithelial cells.

Differential knockdown of TGF-β ligands in a three-dimensional co-culture tumor- stromal interaction model of lung cancer

Background

Transforming growth factor (TGF)-β plays a pivotal role in cancer progression through regulating cancer cell proliferation, invasion, and remodeling of the tumor microenvironment. Cancer-associated fibroblasts (CAFs) are the predominant type of stromal cell, in which TGF-β signaling is activated. Among the strategies for TGF-β signaling inhibition, RNA interference (RNAi) targeting of TGF-β ligands is emerging as a promising tool. Although preclinical studies support the efficacy of this therapeutic strategy, its effect on the tumor microenvironment in vivo remains unknown. In addition, differential effects due to knockdown of various TGF-β ligand isoforms have not been examined. Therefore, an experimental model that recapitulates tumor–stromal interaction is required for validation of therapeutic agents.

Methods

We have previously established a three-dimensional co-culture model of lung cancer, and demonstrated the functional role of co-cultured fibroblasts in enhancing cancer cell invasion and differentiation. Here, we employed this model to examine how knockdown of TGF-β ligands affects the behavior of different cell types. We developed lentivirus vectors carrying artificial microRNAs against human TGF-β1 and TGF-β2, and tested their effects in lung cancer cells and fibroblasts.

Results

Lentiviral vectors potently and selectively suppressed the expression of TGF-β ligands, and showed anti-proliferative effects on these cells. Furthermore, knockdown of TGF-β ligands attenuated fibroblast-mediated collagen gel contraction, and diminished lung cancer cell invasion in three-dimensional co-culture. We also observed differential effects by targeting different TGF-β isoforms in lung cancer cells and fibroblasts.

Conclusions

Our findings support the notion that RNAi-mediated targeting of TGF-β ligands may be beneficial for lung cancer treatment via its action on both cancer and stromal cells. This study further demonstrates the usefulness of this three-dimensional co-culture model to examine the effect of therapeutic agents on tumor–stromal interaction.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-580) contains supplementary material, which is available to authorized users.

Matrix metalloproteinase-9 activates TGF-β and stimulates fibroblast contraction of collagen gels

Matrix metalloproteinase-9 (MMP-9) is a matrix-degrading enzyme implicated in many biological processes, including inflammation. It is produced by many cells, including fibroblasts. When cultured in three-dimensional (3D) collagen gels, fibroblasts contract the surrounding matrix, a function that is thought to model the contraction that characterizes both normal wound repair and fibrosis. The current study was designed to evaluate the role of endogenously produced MMP-9 in fibroblast contraction of 3D collagen gels. Fibroblasts from mice lacking expression of MMP-9 and human lung fibroblasts (HFL-1) transfected with MMP-9 small-interfering RNA (siRNA) were used. Fibroblasts were cast into type I collagen gels and floated in culture medium with or without transforming growth factor (TGF)-β1 for 5 days. Gel size was determined daily using an image analysis system. Gels made from MMP-9 siRNA-treated human fibroblasts contracted less than control fibroblasts, as did fibroblasts incubated with a nonspecific MMP inhibitor. Similarly, fibroblasts cultured from MMP-9-deficient mice contracted gels less than did fibroblasts from control mice. Transfection of the MMP-9-deficient murine fibroblasts with a vector expressing murine MMP-9 restored contractile activity to MMP-9-deficient fibroblasts. Inhibition of MMP-9 reduced active TGF-β1 and reduced several TGF-β1-driven responses, including activity of a Smad3 reporter gene and production of fibronectin. Because TGF-β1 also drives fibroblast gel contraction, this suggests the mechanism for MMP-9 regulation of contraction is through the generation of active TGF-β1. This study provides direct evidence that endogenously produced MMP-9 has a role in regulation of tissue contraction of 3D collagen gels mediated by fibroblasts.

Tumor necrosis factor superfamily member LIGHT induces epithelial-mesenchymal transition in A549 human alveolar epithelial cells

Fibrosis is an abnormal response to organ injury, characterized by accumulation of activated fibroblasts at the sites of injury. Fibroblasts arise from several sources, including resident fibroblasts and circulating fibrocytes that infiltrate organ tissue. Recently, epithelial-mesenchymal transition (EMT) has been recognized as a source of mesenchymal cells. EMT is induced by various growth factors, such as transforming growth factor (TGF)-β1, and enhanced by inflammatory cytokines. Recently the tumor necrosis factor superfamily member LIGHT has been implicated in the pathogenesis of inflammatory disease and airway remodeling in severe asthma. We hypothesized that LIGHT might contribute to the pathogenesis of airway fibrosis via enhancement of EMT. Therefore, we investigated LIGHT's ability to induce EMT. A549 cells were stimulated with LIGHT, TGF-β1 or both for 48h. To estimate EMT, we evaluated the expression of epithelial and mesenchymal markers using immunocytochemistry, Western blotting and quantitative RT-PCR. Signaling pathways for EMT were characterized by Western analysis to detect phosphorylation of Erk1/2 and smad2. LIGHT enhanced TGF-β1-induced EMT both morphologically, by suppressing E-cadherin and enhancing vimentin, and functionally, by enhancing cell contractility. Additionally, LIGHT induced EMT without TGF-β1. Evaluation of the mechanism showed that LIGHT did not induce TGF-β1 production or affect the smad-snai1 pathway. Inhibition of Erk1/2 phosphorylation reduced LIGHT-induced EMT, indicating the Erk1/2 pathway to be a key pathway in LIGHT-induced EMT. In summary, LIGHT enhanced TGF-β1-induced EMT but also induced EMT via the Erk1/2 pathway by itself, without TGF-β1 signaling. LIGHT may contribute to the pathogenesis of airway fibrosis through enhancement of EMT.

Characterization of human lung cancer-associated fibroblasts in three-dimensional in vitro co-culture model

Lung cancer is the most common cause of cancer-related death worldwide. Stromal cancer-associated fibroblasts (CAFs) play crucial roles in carcinogenesis, proliferation, invasion, and metastasis of non-small cell lung carcinoma, and targeting of CAFs could be a novel strategy for cancer treatment. However, the characteristics of human CAFs still remain to be better defined. In this study, we established patient-matched CAFs and normal fibroblasts (NFs), from tumoral and non-tumoral portions of resected lung tissue from lung cancer patients. CAFs showed higher α-smooth muscle actin (α-SMA) expression than NFs, and CAFs clearly enhanced collagen gel contraction. Furthermore, we employed three-dimensional co-culture assay with A549 lung cancer cells, where CAFs were more potent in inducing collagen gel contraction. Hematoxylin and eosin staining of co-cultured collagen gel revealed that CAFs had the potential to increase invasion of A549 cells compared to NFs. These observations provide evidence that lung CAFs have the tumor-promoting capacity distinct from NFs.

Dynamic change in respiratory resistance during inspiratory and expiratory phases of tidal breathing in patients with chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is characterized by persistent airflow limitation consisting of airway obstruction and parenchymal emphysema, with loss of elastic recoil. The forced oscillation technique can detect impairment of lung function by measuring lung impedance during normal tidal breathing. Respiratory resistance (Rrs) in COPD has been well-studied, but the differences in Rrs in the inspiratory and expiratory phases between mild and moderate COPD remain poorly understood. Since airway obstruction in COPD is known to change dynamically during tidal breathing and might affect Rrs, the differences in Rrs during tidal breathing between mild and moderate COPD were evaluated.

METHODS

Mild (n = 13) and moderate (n = 13) COPD patients were recruited at Tokyo University Hospital (Tokyo, Japan). Rrs was measured using MostGraph-01 (Chest MI, Inc, Tokyo, Japan), which depicted Rrs in a frequency-and respiratory cycle-dependent manner in three-dimensional graphics. Rrs was evaluated at 4-35 Hz during tidal breathing.

RESULTS

Rrs changed dynamically during tidal breathing in COPD. The mean Rrs values were significantly greater in the moderate COPD group than in the mild group. The maximal and minimal Rrs values at higher frequencies in the respiratory cycle were significantly greater in moderate COPD. In inspiratory-expiratory breath analysis, the maximal and minimal Rrs values at 20 Hz and 35 Hz were significantly greater in the moderate group, whereas at 4 Hz they did not differ significantly between the groups.

CONCLUSION

Rrs changed dynamically during tidal breathing in patients with COPD. The Rrs values at higher frequencies were greater in moderate COPD than in mild COPD. Rrs at higher frequencies might reflect the degree of airway obstruction in tidal breathing in patients with COPD and might be a useful marker for evaluation of airway obstruction at an early stage of COPD.

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.

The effects of oxidative stress induced by prolonged low-dose diesel exhaust particle exposure on the generation of allergic airway inflammation differ between BALB/c and C57BL/6 mice

We have recently reported that airway inflammatory responses to the oxidative stress induced by prolonged low-dose diesel exhaust particle (DEP) exposure differ markedly between BALB/c and C57BL/6 mice. In the present study, the effects of genetic differences in the response to prolonged low-dose DEP exposure on the generation of ovalbumin-induced allergic airway inflammation were further explored using the same mouse strains. In BALB/c mice, eosinophils and mucous goblet cells in histopathological pulmonary specimens increased significantly after DEP exposure, and were more marked than in C57BL/6 mice. Interleukin (IL)-5 and IL-13 levels in bronchoalveolar lavage (BAL) fluid were increased significantly by DEP exposure only in BALB/c mice. The DEP-induced increases in peribronchial eosinophils and mucous goblet cells in the lung tissues, and of IL-5 and IL-13 in the BAL fluid, were significantly attenuated by the antioxidant N-acetylcysteine. Thus, the effects of prolonged low-dose DEP exposure on the generation of allergic airway inflammation differed markedly between the mouse strains. These differences may be caused by different antioxidant responses to the oxidative stress induced by DEP exposure. Our results contribute more information to the search for genetic susceptibility factors in the response to DEP, and may thus assist in the discovery of new biomarkers for DEP-related disease.

Procaterol inhibits lung fibroblast migration

Fibroblasts are important cells that are involved in modulation of fibrosis after injuries. In some uncontrollable inflammatory processes, excess fibroblasts migrate around the small airway. The pathogenesis of chronic obstructive pulmonary disease is related to fibrosis around the small airways. The aim of the current study was to investigate the effect of procaterol, a second-generation beta (2)-agonist, on migration of human fetal lung fibroblasts (HFL-1) induced by human plasma fibronectin (HFn). Using the blindwell chamber technique, 10(-8) M procaterol inhibited migration of HFL-1 (control, 100%; 10(-8) M, 73.2 +/- 4.9%; n = 6, p < 0.05). The inhibitory effect of procaterol was concentration-dependent. Although a beta 2-receptor inhibitor, ICI 181551, blocked the inhibitory effect of procaterol, a beta 1-receptor inhibitor, atenolol, did not. Because a cyclic AMP-dependent protein kinase (PKA) inhibitor, KT5720, blocked the effect of procaterol, the cyclic AMP-PKA pathway may be involved in the migration inhibitory process. Procaterol, which is prescribed mainly for treatment of bronchial asthma, might be a useful drug for inhibiting lung fibrosis following injuries to the lung.

Tumor necrosis factor-alpha enhances both epithelial-mesenchymal transition and cell contraction induced in A549 human alveolar epithelial cells by transforming growth factor-beta1

Recently, epithelial-mesenchymal transition (EMT) has been reported to contribute to tissue fibrosis through enhanced transforming growth factor (TGF)-beta1 signaling. Tumor necrosis factor (TNF)-alpha has also been implicated in tissue fibrosis. Therefore, the authors investigated whether TNF-alpha affected TGF-beta1-induced EMT. Cultured alveolar epithelial cells (A549 cells) were stimulated with TGF-beta1 (5 ng/mL), with/without TNF-alpha (10 ng/mL). TGF-beta1 induced EMT of A549 cells, with loss of E-cadherin and acquisition of vimentin. Combination of TNF-alpha with TGF-beta1 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-beta1 induced cell contraction, as did TNF-alpha. Moreover, costimulation with TGF-beta1 and TNF-alpha enhanced the cell contraction. Although IFN-gamma suppressed spontaneous cell contraction, it did not suppress cell contraction, which was induced by TGF-beta1. In conclusion, TNF-alpha enhances not only EMT but also cell contraction induced by TGF-beta1. EMT might contribute to tissue fibrosis through induction of cell contraction.

Thyroid transcription factor-1 inhibits transforming growth factor-beta-mediated epithelial-to-mesenchymal transition in lung adenocarcinoma cells

Thyroid transcription factor-1 (TTF-1) is expressed in lung cancer, but its functional roles remain unexplored. TTF-1 gene amplification has been discovered in a part of lung adenocarcinomas, and its action as a lineage-specific oncogene is highlighted. Epithelial-to-mesenchymal transition (EMT) is a crucial event for cancer cells to acquire invasive and metastatic phenotypes and can be elicited by transforming growth factor-beta (TGF-beta). Mesenchymal-to-epithelial transition (MET) is the inverse process of EMT; however, signals that induce MET are largely unknown. Here, we report a novel functional aspect of TTF-1 that inhibits TGF-beta-mediated EMT and restores epithelial phenotype in lung adenocarcinoma cells. This effect was accompanied by down-regulation of TGF-beta target genes, including presumed regulators of EMT, such as Snail and Slug. Moreover, silencing of TTF-1 enhanced TGF-beta-mediated EMT. Thus, TTF-1 can exert a tumor-suppressive effect with abrogation of cellular response to TGF-beta and attenuated invasive capacity. We further revealed that TTF-1 down-regulates TGF-beta2 production in A549 cells and that TGF-beta conversely decreases endogenous TTF-1 expression, suggesting that enhancement of autocrine TGF-beta signaling accelerates the decrease of TTF-1 expression and vice versa. These findings delineate potential links between TTF-1 and TGF-beta signaling in lung cancer progression through regulation of EMT and MET and suggest that modulation of TTF-1 expression can be a novel therapeutic strategy for treatment of lung adenocarcinoma.

Clarithromycin inhibits fibroblast migration

The aim of the current study was to investigate the effect of 14-membered ring macrolide clarithromycin (CAM) on migration induced by human plasma fibronectin (HFn) or on contraction of human fetal lung fibroblasts (HFL-1).

METHODS AND RESULTS

Using the blindwell chamber technique, CAM (10(-5) M) inhibited the migration of HFL-1 60.2+/-4.0% (p<0.05). Other antibiotics, such as ampicillin, minocycline or azithromycin had no effects on HFL-1 migration. The effect of CAM was concentration dependent. HFL-1 migration, stimulated by TXA(2) analog was also inhibited by CAM. Clarithromycin had no effect on HFL-1 mediated gel contraction that was another function of fibroblast at the wound area.

CONCLUSIONS

Clarithromycin may contribute to the regulation of the wound healing response following injury by inhibiting fibroblast migration. These results could represent the therapeutic benefits of CAM.

Airway inflammatory responses to oxidative stress induced by prolonged low-dose diesel exhaust particle exposure from birth differ between mouse BALB/c and C57BL/6 strains

The authors used BALB/c and C57BL/6 mouse strains to search for genetically based differences in response to prolonged (6 months) low-dose (100 microg/m3) diesel exhaust particle (DEP) exposure from birth in terms of airway inflammatory responses. Histopathological assessment showed that inflammatory cells infiltrated the perivascular areas only in C57BL/6 mice. The count of DEP-laden alveolar macrophages in bronchoalveolar lavage (BAL) fluid was significantly greater in BALB/c mice (P < .05) than in C57BL/6 mice. The lymphocyte and eosinophil count in BAL fluid was significantly greater in C57BL/6 mice (P < .05) than in BALB/c mice. Immunoglobulin (Ig) IgG1 and IgG2 levels in serum, and the monocyte chemoattractant protein (MCP)-1 level in BAL fluid were significantly greater in BALB/c mice than in C57BL/6 mice. The interleukin (IL)-12 level in BAL fluid was significantly greater in C57BL/6 mice than in BALB/c mice, but the IL-13 level in BAL fluid was significantly less in BALB/c mice than in C57BL/6 mice. Glutathione S-transferase (GST) mRNA expression and protein production in lung tissues were significantly lower in C57BL/6 mice than in BALB/c mice, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) level in the lung tissues were significantly greater in C57BL/6 mice than in BALB/c mice. In conclusion, prolonged low-dose DEP exposure induces airway inflammatory responses that differ remarkably among mouse strains; these differences are caused by differences in the host defense response to the oxidative stress induced by DEP exposure and may be useful in the development of biomarkers.

Non-infectious bronchiolitis as an early pulmonary complication of hematopoietic stem cell transplantation

Pulmonary complications occur in up to 60% of patients after hematopoietic stem cell transplantation (HSCT), causing significant morbidity and mortality. Among them, non-infectious bronchiolitis is considered a late complication in the form of bronchiolitis obliterans. We report a patient who developed non-infectious bronchiolitis within four weeks after undergoing HSCT for biphenotypic leukemia. Chest CT revealed centrilobular nodules that were reminiscent of diffuse panbronchiolitis, and lymphocytic bronchiolitis was confirmed by biopsy. Infection and bronchiolitis obliterans were ruled out, and the bronchiolitis resolved when leukemia relapsed. This case suggests that bronchiolitis may be another early, non-infectious pulmonary complication of HSCT.

Thrombin and TNF-alpha/IL-1beta synergistically induce fibroblast-mediated collagen gel degradation

Degradation of preexisting and newly synthesized extracellular matrix is thought to play an important role in tissue remodeling. The current study evaluated whether thrombin and TNF-alpha/IL-1beta could collaboratively induce collagen degradation by human fetal lung fibroblasts (HFL-1) and adult bronchial fibroblasts cultured in three-dimensional collagen gels. TNF-alpha/IL-1beta alone induced production of matrix metalloproteinases (MMPs)-1, -3, and -9, which were released in latent form. With the addition of thrombin, the latent MMPs were converted into active forms and this resulted in collagen gel degradation. Part of the activation of MMPs by thrombin resulted from direct activation of MMP-1, MMP-2, MMP-3, and MMP-9 in the absence of cells. In addition, tissue inhibitor of metalloproteinase-1 production was inhibited by the combination of thrombin and TNF-alpha/IL-1beta. These results suggest that thrombin and TNF-alpha/IL-1beta synergize to induce degradation of three-dimensional collagen gels through increasing the production and activation of MMPs, and that this effect is mediated through both direct activation of MMPs by thrombin and indirectly by thrombin activation of fibroblasts. Through such mechanisms, thrombin could contribute to many chronic lung disorders characterized by tissue remodeling.

TGF-beta1 and serum both stimulate contraction but differentially affect apoptosis in 3D collagen gels

Apoptosis of fibroblasts may be key for the removal of cells following repair processes. Contraction of three-dimensional collagen gels is a model of wound healing and remodeling. Here two potent inducers of contraction, TGF-β1 and fetal calf serum (FCS) were evaluated for their effect on fibroblast apoptosis in contracting collagen gels. Human fetal lung fibroblasts were cultured in floating type I collagen gels, exposed to TGF-β1 or FCS, and allowed to contract for 5 days. Apoptosis was evaluated using TUNEL and confirmed by DNA content profiling. Both TGF-β1 and serum significantly augmented collagen gel contraction. TGF-β1 also increased apoptosis assessed by TUNEL positivity and DNA content analysis. In contrast, serum did not affect apoptosis. TGF-β1 induction of apoptosis was associated with augmented expression of Bax, a pro-apoptotic member of the Bax/Bcl-2 family, inhibition of Bcl-2, an anti-apoptotic member of the same family, and inhibition of both cIAP-1 and XIAP, two inhibitors of the caspase cascade. Serum was associated with an increase in cIAP-1 and Bcl-2, anti-apoptotic proteins. Interestingly, serum was also associated with an apparent increase in Bax, a pro-apoptotic protein. Blockade of Smad3 with either siRNA or by using murine fibroblasts deficient in Smad3 resulted in a lack of TGF-β induction of augmented contraction and apoptosis. Contraction induced by different factors, therefore, may be differentially associated with apoptosis, which may be related to the persistence or resolution of the fibroblasts that accumulate following injury.

Smad3 mediates TGF-beta1-induced collagen gel contraction by human lung fibroblasts

Transforming growth factor-beta1 (TGF-beta1) is a key mediator in tissue repair and fibrosis. Using small interference RNA (siRNA), the role of Smad2 and Smad3 in TGF-beta stimulation of human lung fibroblast contraction of collagenous matrix and induction of alpha-SMA and the role of alpha-SMA in contraction were assessed. HFL-1 cells were transfected with Smad2, Smad3 or control-siRNA, and cultured in floating Type I collagen gels +/- -TGF-beta1. TGF-beta1 augmented gel contraction in Smad2-siRNA- and control-siRNA-treated cells, but had no effect in Smad3-siRNA-treated cells. Similarly, TGF-beta1 upregulated alpha-SMA in Smad2-siRNA- and control-siRNA-treated cells, but had no effect on Smad3-siRNA-treated cells. Alpha-SMA-siRNA-treated cells did not contact the collagen gels with or without TGF-beta1, suggesting alpha-SMA is required for gel contraction. Thus, Smad3 mediates TGF-beta1-induced contraction and alpha-SMA induction in human lung fibroblasts. Smad3, therefore, could be a target for blocking contraction of human fibrotic tissue induced by TGF-beta1.

Leukotriene D4 potentiates fibronectin-induced migration of human lung fibroblasts

Fibroblasts play an important role in the repair and remodeling processes following injury. Leukotriene D4 (LTD4) is a potent mediator in inflammatory processes, but the direct effect of cysteinyl leukotrienes on fibroblast migration remains unelucidated. In this study, the effect of the LTD4 on normal human lung fibroblasts (NHLF) chemotaxis induced by human plasma fibronectin (HFn) was investigated using the modified Boyden's chamber technique. LTD4 potentiated NHLF chemotaxis to HFn in concentration-dependent manner. A specific cysteinyl leukotriene receptor type 1 antagonist, pranlukast inhibited this effect, indicating that LTD4 affected cell migration via its specific receptor. The potentiating effect of LTD4 on fibroblast chemotaxis was completely abolished by pertussis toxin (PTX), suggesting that LTD4-induced effect was dependent on PTX-sensitive Gi/o signaling. These findings suggest that LTD4 has a potential to augment fibroblast chemotaxis, and to contribute to regulation of the wound healing and following remodeling in fibrotic processes of the lung.

Thrombin induces collagen gel contraction partially through PAR1 activation and PKC-epsilon

The ability of fibroblasts to contract three-dimensional collagen gels has been used as an in vitro model of the tissue contraction which characterises both normal repair and fibrosis. Among its actions, thrombin can activate the protease-activated receptor (PAR)1 and, thereby, stimulate inflammation and repair. The current study evaluated whether thrombin could stimulate fibroblast-mediated collagen gel contraction by activating PAR1 and whether its downstream signalling depends on protein kinase C (PKC)-epsilon. Human foetal lung fibroblasts (HFL-1) were cultured in three-dimensional collagen gels and the area of the gels was measured by image analyser. Both thrombin and TFLLR, a selective PAR1 agonist, stimulated collagen gel contraction mediated by HFL-1. After RNA interference-mediated PAR1 knockdown in HFL-1, both thrombin and the PAR1 agonist-induced gel contraction were partially inhibited (by 22.4+/-2.2% and 17.6+/-5.6%, respectively). The gel contraction stimulated by thrombin was also reduced by a nonspecific PKC inhibitor and a calcium-independent PKC-epsilon inhibitor. Both thrombin and TFLLR significantly increased PKC-epsilon activity, and this effect was blocked by PAR1 knockdown. Thrombin stimulates collagen gel contraction at least partially through activation of protease-activated receptor 1 and protein kinase C-epsilon, and may contribute to tissue remodelling in inflammatory airway and lung diseases.

Smad3 mediates TGF-β1 induction of VEGF production in lung fibroblasts

Transforming growth factor-beta1 (TGF-beta1) is a key factor in a variety of physiological and pathological processes. Vascular endothelial growth factor (VEGF) is a key angiogenic factor, and vascular change is one of the features of airway remodeling. We examined the effect of TGF-beta1 on VEGF production by fibroblasts from mice lacking expression of Smad2 or Smad3 as well as human lung fibroblasts treated with or without Smad2 or Smad3 siRNA. TGF-beta1 stimulated VEGF production by fibroblasts from Smad2 deficient animals and wildtype animals. In contrast, TGF-beta1 did not affect VEGF production by fibroblasts from Samd3 deficient mice. Similarly, TGF-beta1 failed to stimulate VEGF production by HFL-1 cells treated with Samd3 siRNA but significantly increased VEGF production by the cells treated with Smad2 siRNA. These result suggest that TGF-beta1 stimulation of VEGF production by fibroblasts is regulated by Smad3 but not by Smad2 signaling.

Reversible Cigarette Smoke Extract–Induced DNA Damage in Human Lung Fibroblasts

Cigarette smoke contains thousands of chemicals, many of which may contribute to cytotoxicity and carcinogenesis. Using assays detecting DNA strand breaks (terminal transferase dUTP nick end labeling [TUNEL]) and DNA content (flow cytometry), we evaluated the genotoxic effect of cigarette smoke extract (CSE) on human fetal lung fibroblasts (HFL-1) cultured in three-dimensional collagen gels as well as in monolayer culture. When HFL-1 cells were exposed to CSE, DNA strand breaks were detected in most, as determined by TUNEL. This effect was dependent on CSE concentration, duration of CSE exposure, and the density of HFL-1 cells cast into the collagen gels. Buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis, significantly increased DNA damage induced by 1% CSE, and N-acetylcysteine, a glutathione precursor, blocked 5% CSE from inducing DNA damage. After CSE exposure, most cells were TUNEL-positive, but DNA quantification revealed no hypodiploid cells, indicating that apoptosis was not occurring during the CSE exposure. CSE-induced DNA damage was reversible, and cells proliferated when CSE was removed after 24 h exposure. These results demonstrate that cigarette smoke can induce DNA damage in HFL-1 cells cultured in both three-dimensional collagen gels and monolayer cultures, and that oxidants likely play a role in this damage. Moreover, this DNA damage is reversible, with cells surviving and TUNEL positivity reversing when CSE is removed within 24 h.

IL-4 and IL-13 induce chemotaxis of human foreskin fibroblasts, but not human fetal lung fibroblasts

Through shared receptors, IL-4 and IL-13 have been suggested to regulate not only inflammatory cells, but also to play a role in stimulating fibroblasts during fibrotic processes. Previous studies have shown that IL-4 is a chemoattractant for foreskin fibroblasts. The current study was designed to determine the effect of IL-4 and IL-13 on the migration of two types of fibroblasts: foreskin and human fetal lung fibroblasts (HFL-1). Using the Boyden blindwell chamber method, human foreskin or fetal lung fibroblasts (both 10(6)/mL) were placed in upper wells with various concentrations of IL-4 or IL-13 in the lower wells as chemoattractants. Both IL-4 (1 pg/mL) and IL-13 (100 pg/mL) induced foreskin fibroblast chemotaxis, up to 50 +/- 8 and 24 +/- 7 cells/5 high-power fields, respectively (both p < 0.05). In contrast, neither cytokine induced migration of the lung fibroblasts although both type of cells express IL-4 receptor and IL-13alpha1 receptor. These results suggest that fibroblasts are heterogeneous with regard to their ability to respond to cytokine-driven chemotaxis. Therefore, the role of specific cytokines in mediating fibrotic responses might vary depending on local mesenchymal cell responses.

Cytokines modulate cilomilast response in lung fibroblasts

Fibroblasts, as a major source of extracellular interstitial connective tissue matrix, play an important role in wound healing and the development of fibrosis. The phosphodiesterase (PDE) 4 inhibitor cilomilast inhibits fibroblast chemotaxis and fibroblast-mediated gel contraction. Using the Boyden blindwell chamber chemotaxis assay and the type I collagen gel contraction model, this study investigated whether specific cytokines modulate cilomilast's inhibitory effect through regulation of endogenous PGE(2) production. Human recombinant IL-1beta stimulated PGE(2) production and shifted the cilomilast concentration-dependence curve to the left in both assay systems, indicating increased sensitivity to cilomilast. In contrast, human recombinant IL-4 inhibited PGE(2) production and shifted the cilomilast concentration-dependence curve to the right in both systems. In summary, the inhibitory effect of cilomilast on fibroblast migration and collagen gel contraction is modulated by IL-1beta and IL-4 through regulation of PGE(2) production.

Methotrexate induces interleukin-8 production by human bronchial and alveolar epithelial cells

Methotrexate (MTX) has been widely used for the treatment of a variety of tumours as well as for inflammatory diseases. MTX-induced pneumonitis has been a serious unpredictable side effect of the treatment and an important clinical problem. However, its mechanism remains largely unclear. Possible causes include allergic, cytotoxic or immunologic reactions to this agent. To elucidate the proinflammatory mechanism of MTX-induced pneumonitis, we evaluated the effect of MTX on the production of IL (interleukin)-8 by human bronchial and alveolar epithelial cells in vitro and the role of p38 MAPK (mitogen-activated protein kinase) in order to clarify the intracellular signal regulating IL-8 expression. MTX induced IL-8 secretion by human bronchial and alveolar epithelial cells in a dose- and time-dependent manner within the range of the clinically observed serum concentrations. Although addition of LPS (lipopolysaccharide) and glucose showed no significant enhancing effect, addition of IL-1β or TNF-α (tumour necrosis factor-α) with MTX to bronchial epithelial cells showed a significant augmenting effect. SB203580, the specific inhibitor of p38 MAPK, inhibited MTX-induced IL-8 production. MTX induced the phosphorylation of Thr180 and Tyr182 on p38 MAPK. These results suggest that MTX activates bronchial and alveolar epithelial cells to induce IL-8 production through p38 MAPK, which might play an important role as one of the mechanisms of MTX-induced lung inflammation.

Cigarette smoke stimulates MMP-1 production by human lung fibroblasts through the ERK1/2 pathway

An imbalance between proteases and anti-proteases is believed to play an important role in the pathogenesis of emphysema. In this study, we explored the hypothesis that cigarette smoke can alter tissue structure through an effect on the release of matrix metalloproteinase-1 (MMP-1) and type I tissue inhibitor of metalloproteinases (TIMP-1). Cigarette smoke extract (CSE) significantly stimulated pro-MMP-1 production (determined by ELISA and immunoblots) and mRNA expression (by real-time RT-PCR) by human fetal lung fibroblasts (HFL-1) in a concentration-dependent manner (2.5-10%). High concentrations of CSE (10%) could potentially activate the latent form of MMP-1 as the high molecular weight (52 kDa) form was converted into a low molecular weight (42 kDa) form consistent with active MMP-1. TIMP-1 production, however, was not significantly altered by the concentrations of CSE tested. After 30 min exposure, CSE significantly induced ERK1/2 phosphorylation, which then gradually decreased from 90 minutes to 3 hours. PD98059, a specific inhibitor of ERK-MAPK, significantly blocked the CSE effect on ERK1/2 phosphorylation. Furthermore, PD98059 significantly inhibited the CSE effect on MMP-1 production and mRNA expression by fibroblasts. These results suggest that cigarette smoke stimulates production and likely activates MMP-1 through activating ERK1/2 signal transduction pathway. By inducing MMP-1, cigarette smoke may result in excess tissue destruction and contribute to the development of emphysema.

Interferon-gamma inhibits transforming growth factor-beta production in human airway epithelial cells by targeting Smads

Because interferon (IFN)-gamma may attenuate pulmonary fibrosis, we hypothesized that IFN-gamma may regulate transforming growth factor (TGF)-beta production by airway epithelial cells. Human bronchial epithelial cells (HBECs) were incubated with IFN-gamma +/- TGF-beta1, -beta3, or interleukin (IL)-1beta, platelet-derived growth factor (PDGF), epidermal growth factor, and IL-4. TGF-beta2 protein was measured by enzyme-linked immunosorbent assay and mRNA expression for TGF-beta2, Smad 2, 3, 4, and 7 was evaluated by real-time reverse transcriptase-polymerase chain reaction. Localization of Smads 2, 3, 4, and 7 was evaluated by immunostaining. Exogenous TGF-beta1 and 3, IL-1beta, PDGF, and IL-4 enhanced TGF-beta2 release by HBECs (P < 0.01). IFN-gamma reduced basal and TGF-beta or IL-4-augmented TGF-beta2 release, but had little effect on IL-1beta- or PDGF-augmented TGF-beta2 release. IFN-gamma stimulated Smad 7 protein and mRNA expression. Smad 7-specific siRNA decreased Smad 7 protein expression both in control and IFN-gamma-treated cells. The inhibitory effect of IFN-gamma on TGF-beta2 production was abrogated when the HBECs were treated with Smad 7 siRNA. These results suggest that IFN-gamma down regulates TGF-beta2 production by HBECs by regulating Smad 7. Through this mechanism, IFN-gamma may play an important role in tissue remodeling.

Budding of crystalline domains in fluid membranes

Crystalline domains embedded in fluid membrane vesicles are studied by Monte Carlo simulations of dynamically triangulated surfaces and by scaling arguments. A budding transition from a caplike state to a budded shape is observed for increasing spontaneous curvature C0 of the crystalline domain as well as increasing line tension lambda. The location of the budding transition is determined as a function of C0, lambda, and the radius R(A) of the crystalline domain. In contrast to previous theoretical predictions, it is found that budding occurs at a value of the spontaneous curvature C0, that is always a decreasing function of the domain size R(A). Several characteristic scaling regimes are predicted. The distribution of five- and sevenfold disclinations as the budding transition is approached is determined, and the dynamics of the generation of defects is studied.

Diesel exhaust particles upregulate eotaxin gene expression in human bronchial epithelial cells via nuclear factor-kappa B-dependent pathway

Fine particles derived from diesel engines, diesel exhaust particles (DEP), have been shown to augment gene expression of several inflammatory cytokines in human airway epithelial cells in vitro. However, it remains unclear whether or not DEP have any effect on the expression and production of eotaxin, an important chemokine involved in eosinophil recruitment into the airways. We studied the effects of DEP by using a conventional suspended DEP and by a recently established in vitro cell exposure system to diesel exhaust (Abe S, Takizawa H, Sugawara I, and Kudoh S, Am J Respir Cell Mol Biol 22: 296-303, 2000). DEP showed a dose-dependent stimulatory effect on eotaxin production by normal human peripheral airway epithelial cells as well as by bronchial epithelial cell line BET-1A as assessed by specific ELISA. mRNA levels increased by DEP were shown by RT-PCR. DEP showed an additive effect on IL-13-stimulated eotaxin expression. DEP induced NF-kappaB activation by EMSA as previously reported but did not induce signal transducer and activator of transcription (STAT) 6 activation according to Western blot analysis. Finally, antioxidant agents (N-acetyl cysteine and pyrrolidine dithiocarbamate), which inhibited NF-kappaB activation but failed to affect STAT6 activation, almost completely attenuated DEP-induced eotaxin production, whereas these agents failed to attenuate IL-13-induced eotaxin production. These findings suggested that DEP stimulated eotaxin gene expression via NF-kappaB-dependent, but STAT6-independent, pathways.

Cigarette smoke extract inhibits chemotaxis and collagen gel contraction mediated by human bone marrow osteoprogenitor cells and osteoblast-like cells

Cell migration and matrix remodeling are key events in tissue repair and restructuring. Osteoblasts are responsible for the production of new bone matrix during bone remodeling. The activity of these cells can be modulated by a number of factors. The current study evaluated the hypothesis that cigarette smoke extract can alter repair and remodeling responses of human osteoprogenitor cells and osteoblast-like cells and, therefore, could explain one mechanism by which cigarette smoking leads to osteoporosis. Human osteoprogenitor cells were isolated from normal human bone marrow and maintained in culture under either control conditions or conditions that induced differentiation into osteoblast-like cells. Both cell types migrated toward fibronectin and PDGF-BB as chemoattractants. Neither responded to TGF-beta1. The osteoprogenitor cells were more active in their chemotactic response. The chemotactic response of both cell types was inhibited by cigarette smoke extract in a concentration-dependent manner. Both cell types, when cultured in three-dimensional native collagen gels maintained in floating culture, induced contraction of their surrounding matrices. Contraction was augmented by serum, PDGF-BB, and TGF-beta1. Osteoprogenitor cells were less active in inducing contraction than were osteoblast-like cells. Contraction of both cell types was inhibited by cigarette smoke extract. Cigarette smoke extract also inhibited the production of fibronectin by both cell types maintained in three-dimensional culture. Addition of exogenous fibronectin partially restored the ability of the cells to contract three-dimensional collagen gels. The current study demonstrates that cigarette smoke can interfere with the ability of bone cells to participate in repair and remodeling events. Such an effect may be one mechanism leading to the development of osteoporosis.

Glucocorticoids modulate TGF-beta production by human fetal lung fibroblasts

TGF-beta1 is thought to play a central role in pulmonary fibrosis inducing fibroblast differentiation and extracellular matrix synthesis. In human lung fibroblasts, it is still unclear how various TGF-beta isoforms affect TGF-beta production and whether glucocorticoids, commonly used agents to treat fibrotic lung disease, modulate these processes. To this end, human fetal lung fibroblasts (HFLF) were cultured with various concentrations of glucocorticoids (budesonide, dexamethasone or hydrocortisone) with and without TGF-beta1, -beta2, or -beta3. Post-culture media were collected for ELISA assays of TGF-beta1, -beta2, and -beta3. TGF-beta mRNA was assessed by real time RT-PCR. Smad 2, 3, and 4 and AP-1 complex (c-fos and c-Jun) cellular localization were evaluated by immunostaining. TFG-beta2 and -beta3 stimulated TGF-beta1 production significantly (p < 0.01 relative to control). TGF-beta1 stimulated TGF-beta2 production (p < 0.01 relative to control). TGF-beta3 was undetectable. Glucocorticoids significantly inhibited TGF-beta1 and TGF-beta2 production and reduced expression of the up-regulated TGF-beta1 and TGF-beta2 mRNA induced by exogenous TGF-beta1, -beta2, or -beta3 (p < 0.01 for each) but had no effect on Smads. Although c-jun-related nuclear staining was not intensified in TGF-beta-stimulated cells, it was reduced by glucocorticoids. Thus, TGF-beta isoforms may stimulate production of various TGF-beta isoforms in the lung. Glucocorticoids then may block TGF-beta production by modulating mRNA levels and c-Jun.

Effect of cigarette smoke on fibroblast-mediated gel contraction is dependent on cell density

Cigarette smoke exposure has been associated with a variety of diseases, including emphysema. The current study evaluated the interaction of cell density and cigarette smoke extract (CSE) on fibroblast contraction of collagen gels. Protein levels of transforming growth factor (TGF)-beta1, fibronectin, PGE(2), and TGF-beta1 mRNA were quantified. Although both 5 and 10% CSE inhibited contraction by low-density fibroblasts (1 x 10(5) cell/ml), only 5% CSE augmented contraction in higher-density cultures (3-5 x 10(5) cells/ml). CSE also inhibited fibronectin and TGF-beta1 production in low-density cultures but stimulated fibronectin production in high-density cultures. Active TGF-beta1 was readily detectable only in higher-density cultures and was markedly augmented by 5% CSE. In contrast, although TGF-beta1 mRNA expression was inhibited in high-density cultures by 10% CSE, expression was increased in the presence of 5% CSE. These results suggest that CSE-induced inhibition of low-density fibroblast contraction is due to inhibition of fibronectin production, whereas CSE's stimulatory effect on high-density cells is the result of increased release of TGF-beta1. These effects may help explain the varied pathologies associated with exposure to cigarette smoke.

Ultrafine carbon black particles inhibit human lung fibroblast-mediated collagen gel contraction

Both acute and chronic exposure to particulates have been associated with increased mortality and morbidity from a number of causes, including chronic obstructive pulmonary disease and other chronic lung diseases. The current study evaluated the hypothesis that ultrafine carbon particles, a component of ambient particulates, could affect tissue repair. To assess this, the three-dimensional collagen gel contraction model was used. Ultrafine carbon black particles, but not fine carbon black, inhibited fibroblast-mediated collagen gel contraction. Although previous research has indicated that inflammatory effects of ultrafine carbon black particles are mediated by oxidant mechanisms, the current study suggests that ultrafine carbon black's inhibition of fibroblast gel contraction is mediated by the binding of both fibronectin and transforming growth factor (TGF)-beta to the ultrafine particles. Binding of TGF-beta was associated with a reduction in nuclear localization of Smads, indicative of inhibition of TGF-beta signal transduction. There was also a decrease in fibronectin mRNA, consistent with a decrease in TGF-beta-mediated response. Taken together, these results demonstrate the ability of ultrafine particles to contribute to altered tissue repair and extend the known mechanisms by which these biologically active particles exert their effects.

Glucocorticoids modulate TGF-beta production

TGF-beta is thought to play a central role in pulmonary fibrosis inducing fibroblast differentiation and extracellular matrix synthesis. In human lung fibroblasts, it is still unclear how various TGB-beta isoforms affect TGF-beta production and whether glucocorticoids, commonly used agents to treat fibrotic lung disease, modulate these processes. To this end, human fetal lung fibroblasts (HFL-1) were cultured with various concentrations of glucocorticoids (budesonide, dexamethasone or hydrocortisone) with and without TFG-beta1, -beta2, and -beta3. TGF-beta mRNA was assessed by real time RT-PCR. Smad 2, 3, and 4 and AP-1 complex (c-fos and c-Jun) cellular localization were evaluated by immunostaining. TGF-beta2 and -beta3 stimulated TGF-beta1 production significantly (p < 0.01 relative to control). TGF-beta1 stimulated TGF-beta2 production (p < 0.01 relative to control). TGF-beta3 was undetectable. Glucocorticoids significantly inhibited TGF-beta1 and -beta2 production and reduced expression of the upregulated TGF-beta1 and -beta2 mRNA induced by exogenous TGF-beta1, -beta2 or -beta3 (p < 0.01 for each) but had no effect on Smads. Although c-jun-related nuclear staining was not intensified in TGF-beta-stimulated cells, it was reduced by glucocorticoids. Thus, TGF-beta isoforms may stimulate production of various TGF-beta isoforms in the lung. Glucocorticoids then may block TGF-beta production by modulating mRNA levels and c-Jun.

Nerve growth factor stimulates fibronectin-induced fibroblast migration

Nerve growth factor (NGF), a polypeptide with well-known actions on neurons, is believed to play a role in the process of tissue repair. The aim of this study was to investigate the effect of NGF on human fetal lung fibroblast (HFL-1)-mediated type I collagen gel contraction and on chemotaxis of the cells with the use of the blind-well chamber technique. Neither collagen gel contraction nor the chemotaxis of HFL-1 cells was affected by NGF (100 ng/mL) alone. However, NGF significantly increased HFL-1 chemotaxis to human fibronectin (20 microg/mL) and platelet-derived growth factor-BB (PDGF-BB, 10 ng/mL), by 41.8% +/- 11.4% and 47.7% +/- 6.6%, respectively. Checkerboard analysis showed stimulation of both chemotaxis and chemokinesis. NGF appeared to affect the rate of migration. After 12 hours, control cells had migrated as much as NGF-treated cells. The effect of NGF was blocked by the tyrosine kinase receptor A inhibitor K-252a, suggesting that the biological action of NGF on fibroblast chemotaxis is mediated through this tyrosine kinase receptor. Our findings suggest that by increasing the rate at which fibroblasts migrate in response to chemoattractants, NGF can modulate the speed and intensity of a repair response and may therefore represent a valid therapeutic target for a variety of diseases.

Phosphodiesterase 4 inhibitor cilomilast inhibits fibroblast-mediated collagen gel degradation induced by tumor necrosis factor-alpha and neutrophil elastase

Tissue destruction, resulting in emphysema, can be a consequence of several pathologic processes. The current study evaluated the effects of the phosphodiesterase (PDE)4 inhibitor, cilomilast, and other PDE inhibitors on the ability of fibroblasts to degrade extracellular matrix. Using the three-dimensional collagen gel culture system, fibroblasts (HFL-1) were cultured with tumor necrosis factor (TNF)-alpha, known to induce matrix metalloproteinase (MMP) release, and/or neutrophil elastase (NE), which can induce MMP activation. On Day 4, gels containing TNF-alpha and NE were significantly degraded (20.8 +/- 2.9% of original collagen content). Cilomilast (10 micro M) inhibited this degradation (84.4 +/- 8.4%). Amrinone, a PDE3 inhibitor, and zaprinast, a PDE5 inhibitor, had no effect. Gelatin zymography and immunoblotting revealed that fibroblasts cultured with TNF-alpha released increased amounts of latent MMP-1 and -9. The addition of NE resulted in the conversion of MMP-1 and -9 to their active forms, indicative of collagen degradation. Cilomilast inhibited the release of MMP-1 and -9, as well as conversion of MMP-1 to its active form. Using real-time PCR analysis, cilomilast's effect on MMP-1 release was not associated with the proteinase's mRNA expression, suggesting that the inhibition of release is regulated at the post-transcriptional level. These results suggest that cilomilast may be a potentially effective therapeutic agent in diseases characterized by excessive tissue destruction, such as emphysema.

PGD(2) modulates fibroblast-mediated native collagen gel contraction

Repair of tissues is a necessary step in restoring tissue function following injury consequent to inflammation. Many inflammatory mediators are capable of modulating not only the activity of "inflammatory cells" but also of modulating functions of parenchymal cells that may contribute to repair. Disordered repair is believed to contribute to tissue dysfunction in many inflammatory diseases, including bronchial asthma. The current study evaluated the ability of prostaglandin D(2) (PGD(2)) to modulate fibroblast repair using the in vitro contraction of three-dimensional native collagen gels as a model system. PGD(2) stimulated gel contraction in a concentration- and time-dependent manner. In contrast, the PGD(2) analog BW245C inhibited contraction. Both effects were blocked by a DP-receptor blocker (AH6809). Neither TP receptor blocker SQ29548 nor protein kinase (PK) A antagonist KT5720 hand an effect on PGD(2)-stimulated contraction, suggesting action through a novel prostaglandin D receptor. PKC inhibitor calphostin-C (10(-6) M) blocked the PGD(2) stimulation of gel contraction. A calcium-independent PKC-epsilon inhibitor (Ro31-8220), but not calcium-dependent PKC-alpha and -beta inhibitors, also blocked the PGD(2) effect on contraction, implying a role for a calcium-independent pathway. This study, therefore, supports a role for PGD(2) in tissue repair and remodeling. These effects of PGD(2) appear to be mediated through receptor-signal transduction pathways different from the cAMP-PKA pathways mediating the proinflammatory activity of PGD(2), creating the possibility for selective therapeutic manipulation.