Katsuyuki Tomita

Increased periostin associates with greater airflow limitation in patients receiving inhaled corticosteroids.

BACKGROUND Periostin, an extracellular matrix protein, contributes to subepithelial thickening in asthmatic airways, and its serum levels reflect airway eosinophilic inflammation. However, the relationship between periostin and the development of airflow limitation, a functional consequence of airway remodeling, remains unknown. OBJECTIVE We aimed to determine the relationship between serum periostin levels and pulmonary function decline in asthmatic patients on inhaled corticosteroid (ICS) treatment. METHODS Two hundred twenty-four asthmatic patients (average age, 62.3 years) treated with ICS for at least 4 years were enrolled. Annual changes in FEV1, from at least 1 year after the initiation of ICS treatment to the time of enrollment or later (average, 16.2 measurements over 8 years per individual), were assessed. At enrollment, clinical indices, biomarkers that included serum periostin, and periostin gene polymorphisms were examined. Associations between clinical indices or biomarkers and a decline in FEV1 of 30 mL or greater per year were analyzed. RESULTS High serum periostin levels (≥ 95 ng/mL) at enrollment, the highest treatment step, higher ICS daily doses, a history of admission due to asthma exacerbation, comorbid or a history of sinusitis, and ex-smoking were associated with a decline in FEV1 of 30 mL or greater per year. Multivariate analysis showed that high serum periostin, the highest treatment step, and ex-smoking were independent risk factors for the decline. Polymorphisms of periostin gene were related to higher serum periostin levels (rs3829365) and a decline in FEV1 of 30 mL or greater per year (rs9603226). CONCLUSIONS Serum periostin appears to be a useful biomarker for the development of airflow limitation in asthmatic patients on ICS.

Adenosine 3′,5′-Cyclic Monophosphate (cAMP)-Dependent Inhibition of IL-5 from Human T Lymphocytes Is Not Mediated by the cAMP-Dependent Protein Kinase A

IL-5 is implicated in the pathogenesis of asthma and is predominantly released from T lymphocytes of the Th2 phenotype. In anti-CD3 plus anti-CD28-stimulated PBMC, albuterol, isoproterenol, rolipram, PGE2, forskolin, cholera toxin, and the cAMP analog, 8-bromoadenosine cAMP (8-Br-cAMP) all inhibited the release of IL-5 and lymphocyte proliferation. Although all of the above compounds share the ability to increase intracellular cAMP levels and activate protein kinase (PK) A, the PKA inhibitor H-89 failed to ablate the inhibition of IL-5 production mediated by 8-Br-cAMP, rolipram, forskolin, or PGE2. Similarly, H-89 had no effect on the cAMP-mediated inhibition of lymphocyte proliferation. Significantly, these observations occurred at a concentration of H-89 (3 μM) that inhibited both PKA activity and CREB phosphorylation in intact cells. Additional studies showed that the PKA inhibitors H-8, 8-(4-chlorophenylthio) adenosine-3′,5′-cyclic monophosphorothioate Rp isomer, and a myristolated PKA inhibitor peptide also failed to block the 8-Br-cAMP-mediated inhibition of IL-5 release from PBMC. Likewise, a role for PKG was considered unlikely because both activators and inhibitors of this enzyme had no effect on IL-5 release. Western blotting identified Rap1, a downstream target of the cAMP-binding proteins, exchange protein directly activated by cAMP/cAMP-guanine nucleotide exchange factors 1 and 2, in PBMC. However, Rap1 activation assays revealed that this pathway is also unlikely to be involved in the cAMP-mediated inhibition of IL-5. Taken together, these results indicate that cAMP-elevating agents inhibit IL-5 release from PBMC by a novel cAMP-dependent mechanism that does not involve the activation of PKA.

Expression of GATA family of transcription factors in T-cells, monocytes and bronchial biopsies

GATA-binding proteins are a subfamily of zinc finger transcription factors with six members (GATA-1-6) that interact with the GATA deoxyribonucleic acid (DNA) sequence. This sequence is found in the regulatory regions of many genes including those encoding T-helper 2 (Th2)-like cytokines, receptors, adhesion molecules and enzymes, which may be important in the pathogenesis of bronchial asthma. The expression of GATA-3, 4 and -6 was investigated in peripheral blood T-lymphocytes and monocytes and bronchial biopsies from 11 normal subjects and 10 steroid-naive asthmatic patients. Using Western blot analysis, T-cells from asthmatic subjects expressed 5 times the level of GATA-3 compared to that in normals. Confocal microscopy indicated that GATA-3 expression was both nuclear and cytoplasmic. GATA DNA binding complex containing GATA-3 was elevated in Th2 cells as determined by electrophorectic mobility shift assay. In contrast, monocytes from normal and asthmatic subjects expressed GATA-4 and -6 in equal amounts, but no GATA-3 was found. Using immunohistochemistry in bronchial biopsies, epithelial cells expressed high levels of GATA-3, GATA-4 and GATA-6 proteins. Comparison of Western blots of bronchial biopsies showed no significant differences between normal and asthmatic subjects. In conclusion, the increased expression of GATA-3 in asthmatic T-cells may underlie augmented T-helper 2-like cytokines in this disease. However, the unaltered GATA-3 expression in epithelial cells suggests a distinct role for GATA-3 in these cells unrelated to T-helper 2-like cytokine release. Finally, no evidence was found for an increased expression of GATA-4 and GATA-6 in asthma.

Trichostatin A, a histone deacetylase inhibitor, down-regulates interleukin-12 transcription in SV-40-transformed lung epithelial cells.

Inhibition of histone deacetylation results in increased gene expression. Trichostatin (Ts)A, a specific histone deacetylase (HDAC) inhibitor, up-regulates transcription of some genes but represses expression of others. We quantified histone acetylation in SV-40-transformed lung epithelial cells using flow cytometry. Further, to evaluate the effect of TsA on transcription of genes associated with airway inflammation, we measured interleukin (IL)-8 production by enzyme-linked immunosorbent assay as well as IL-12 transcription by reverse transcription-polymerase chain reaction, in the transformed cells after stimulation with lipopolysaccharide (LPS) in the presence of TsA. Pretreatment of cells with TsA before LPS stimulation induced hyperacetylation of histones (especially in the S phase of the cell cycle), enhanced IL-8 production, and suppressed IL-12p35 and IL-12p40 mRNA accumulation. Thus we have demonstrated a useful way to detect hyperacetylation at the single-cell level, as well as the ability of an HDAC inhibitor to repress genes in epithelial cells.

Interleukin‐18‐deficient mice exhibit diminished chronic inflammation and airway remodelling in ovalbumin‐induced asthma model

Interleukin (IL)‐18, which is produced by activated monocytes/macrophages and airway epithelial cells, is suggested to contribute to the pathophysiology of asthma by modulating airway inflammation. However, the involvement of IL‐18 on modulating chronic airway inflammation and airway remodelling, which are characterized in a refractory asthma model exposed to long‐term antigen, has not been investigated sufficiently. We examined the role of IL‐18 in chronic airway inflammation and airway remodelling by long‐term antigen exposure. IL‐18‐deficient and C57BL/6‐wild‐type mice were sensitized by ovalbumin (OVA) and were then exposed to aerosolized OVA twice a week for 12 weeks. We assessed airway inflammation by assessing the infiltration of cells into the airspace and lung tissues, and airway remodelling by airway mucus expression, peribronchial fibrosis and smooth muscle thickness. In IL‐18‐deficient mice, when exposed to OVA, the total cells and neutrophils of the bronchoalveolar lavage fluid (BALF) were diminished, as were the number of infiltrated cells in the lung tissues. IL‐18‐deficient mice exposed to OVA after 12 weeks showed significantly decreased levels of interferon (IFN)‐γ, IL‐13 and transforming growth factor (TGF)‐β1 in the BALF. The airway hyperresponsiveness to acetyl‐β‐methacholine chloride was inhibited in IL‐18‐deficient mice in comparison with wild‐type mice. In addition, IL‐18‐deficient mice exposed to OVA had fewer significant features of airway remodelling. These findings suggest that IL‐18 may enhance chronic airway inflammation and airway remodelling through the production of IFN‐γ, IL‐13 and TGF‐β1 in the OVA‐induced asthma mouse model.

The Strategy for Predicting Future Exacerbation of Asthma Using a Combination of the Asthma Control Test and Lung Function Test

Background. Various factors have been reported to be useful for predicting future exacerbations. Objective. This study was intended to determine a usefulness of a combination of a patient-based questionnaire, such as the Asthma Control Test (ACT) score with objective assessments, such as forced expiratory volume in 1 second (FEV1) and/or exhaled nitric oxide (FENO), for predicting future exacerbations in adult asthmatics. Methods. We therefore enrolled 78 subjects with mild to moderate asthma, who were clinically stable for 3 months who all had been regularly receiving inhaled steroid treatment. All subjects underwent a routine assessment of asthma control including the ACT score, spirometry, and FENO, and then were followed up until a severe exacerbation occurred. The predictors of an increased risk of severe exacerbation were identified and validated using decision trees based on a classification and regression tree (CART) analysis. The properties of the developed models were the evaluated with the area under the ROC curve (AUC) (95% confidence interval [CI]). Results. The CART analysis automatically selected the variables and cut-off points, the ACT score ≤23 and FEV1 ≤ 91.8%, with the greatest capacity for discriminating future exacerbations within one year or not. When the probalility was calculated by the likelihood ratio of a positive test (LP), the ACT score ≤23 was identified with a 60.3% probability, calculated by 1.82 of LP, whereas the combined ACT score ≤23 and the percentage of predicted FEV1 ≤ 91.8% were identified with an 85.0% probability, calculated by an LP score of 5.43, for predicting future exacerbation. Conclusion. These results demonstrated that combining the ACT score and percentage of predicted FEV1, but not FENO, can sufficiently stratify the risk for future exacerbations within one year.

MCM2 and Ki-67 Expression in Human Lung Adenocarcinoma: Prognostic Implications

Objective: The expressions of minichromosome maintenance protein 2 (MCM2), Ki-67, and p53 were examined to analyze their pathobiological significance in human lung adenocarcinomas. Methods: We performed Western blot analysis in six human lung adenocarcinoma cell lines and immunohistochemistry in 145 surgically removed adenocarcinomas to examine the MCM2 expression. Labeling indices (LIs; %) of MCM2, Ki-67, and p53 in the tumor cells were compared with clinicopathological profiles and overall survival rates. Results: MCM2 protein was detected in all cell lines examined, with specific bands. MCM2 LIs were significantly correlated with sex, histological type, differentiation, pathological stage, and LIs of Ki-67 and p53 (p < 0.05). Significantly higher LIs of MCM2 and Ki-67 were noted in the 122 non-pure bronchioloalveolar carcinomas than in the 23 pure bronchioloalveolar carcinomas (p < 0.01), and the prognosis was poorer in the former than in the latter (p < 0.01). Sex, pathological stage, and high LIs of MCM2 and/or Ki-67 were independent prognostic factors (p < 0.05). Conclusion: High LIs of MCM2 and/or Ki-67 suggest a poor prognosis in patients with lung adenocarcinoma (non-pure bronchioloalveolar carcinoma).

Functional assay of NF-κB translocation into nuclei by laser scanning cytometry: inhibitory effect by dexamethasone or theophylline

Abstract Nuclear factor-κ B (NF-κB)/Rel transcription factors play an important role in the inducible regulation of a variety of cytokine genes in epithelial cells. We assessed accumulation of fluorescence-stained NF-κB into propi-dium iodide-stained nuclei using laser scanning cytometry. “Activity-specific” antibodies to the Rel A (p65) and NF-κB1 (p50) subunits of NF-κB were detected in the nuclei of A549 cells (an immortalized human type II alveolar epithelial cell line). Exposure to TNF-alpha caused p65 and p50 to translocate into nuclei in a dose- and time-dependent manner. Preincubation with dexamethasone for 24 h or 30 min, or with theophylline for 30 min before TNF-alpha stimulation attenuated the nuclear translocation of Rel A and p50. These findings suggest that theophylline, as well as dexamethasone, may inhibit translocation of NF-κB.

Differential expression of IL-10 receptor by epithelial cells and alveolar macrophages

Background:  Interleukin (IL)‐10 is a pleiotropic cytokine with a broad spectrum of immunosuppressive and anti‐inflammatory effects. IL‐10 secretion from alveolar macrophages is defective in patients with asthma and lower concentrations of IL‐10 are found in bronchoalveolar lavage (BAL) from asthmatic patients than in normal control subjects. Reduced IL‐10 may result in exaggerated and more prolonged inflammatory responses in asthmatic airways. IL‐10 acting through the IL‐10 receptor (IL‐10R) stimulates the transcription factors STAT1 and STAT3.

Integrating longitudinal information on pulmonary function and inflammation using asthma phenotypes.

From the Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Md; the Clinical Research Directorate/CMRP, Leidos Biomedical Research (formerly SAIC-Frederick), Frederick National Laboratory for Cancer Research, Frederick, Md; the Division of Allergy and Immunology, Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio; the Clinical Center and the Department of Laboratory Medicine, National Institutes of Health, Bethesda, Md; and the Department of Internal Medicine, Virginia Commonwealth University, Richmond, Va. E-mail: jdmilner@ niaid.nih.gov. Or: twilson@mail.nih.gov. Supported by National Institutes of Health (NIH) U19AI77435, and in part by grants from Food Allergy Research and Education (formerly the Food Allergy and Anaphylaxis Network [FAAN], the Food Allergy Project [FAP], and the Food Allergy Initiative [FAI]), the Buckeye Foundation, and the Campaign Urging Research for Eosinophilic Diseases (CURED) Foundation. This project has been funded in part with federal funds from the National Cancer Institute, NIH, under contract no. HHSN261200800001E. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services nor does mention of trade names, commercial products, or organizations imply endorsement by the US Government. This research was supported in part by the NIAID. Disclosure of potential conflict of interest: N. Jones has received a grant from LEIDOS. J. P. Abonia has received grants from the National Institutes of Health (NIH), Food Allergy Research and Education (FARE), the Food Allergy & Anaphylaxis Network, the Buckeye Foundation, and the Campaign Urging Research for Eosinophilic Diseases Foundation. M. E. Rothenberg has received research support from the NIH, the CURED Foundation, FARE, and the Buckeye Foundation; is a board member of the International Eosinophil Society Steering Committee and the APFED Medical Panel; has consultant arrangements with Immune Pharmaceuticals, Pluristem Pharmaceuticals, Receptos, and Novartis; is an inventor on patents submitted and owned by Cincinnati Children’s Hospital Medical Center; receives royalties from Teva Pharmaceuticals; and has stock/stock options in Immune Pharmaceuticals and Receptos. L. B. Schwartz is on the board of directors for the Clinical Immunology Society and the Asthma and Allergy Foundation of America; has consultant arrangements with Sanofi Aventis, Dyax, and Viropharma; has received grants from CSL Behring and Dyax; receives royalties for licensing arrangements through VCU Tech Transfer; and receives honorarium as Associate Editor of the Journal of Clinical Immunology. The rest of the authors declare that they have no relevant conflicts of interest.