Asthma and inflammation

Cytokines and cytokine-specific therapy in asthma

Asthma is increasing in prevalence worldwide. It is characterized by typical symptoms and variable airway obstruction punctuated with episodes of worsening symptoms known as exacerbations. Underlying this clinical expression of disease is airway inflammation and remodeling. Cytokines and their networks are implicated in the innate and adaptive immune responses driving airway inflammation in asthma and are modulated by host-environment interactions. Asthma is a complex heterogeneous disease, and the paradigm of Th2 cytokine-mediated eosinophilic inflammation as a consequence of allergic sensitization has been challenged and probably represents a subgroup of asthma. Indeed, as attention has switched to the importance of severe asthma, which represents the highest burden both to the patient and health care provider, there is an increasing recognition of inflammatory subphenotypes that are likely to be driven by different cytokine networks. Interestingly, these networks may be specific to aspects of clinical expression as well as inflammatory cell profiles and therefore present novel phenotype-specific therapeutic strategies. Here, we review the breadth of cytokines implicated in the pathogenesis of asthma and focus upon the outcomes of early clinical trials conducted using cytokines or cytokine-blocking therapies.

RG-II from Panax ginseng C.A. Meyer suppresses asthmatic reaction

In asthma, T helper 2 (T(H)2)-type cytokines such as interleukin (IL)-4, IL-5, and IL-13 are produced by activated CD4(+) T cells. Dendritic cells played an important role in determining the fate of naive T cells into either T(H)1 or T(H)2 cells. We determined whether RG-II regulates the T(H)1/T(H)2 immune response by using an ovalbumin-induced murine model of asthma. RG-II reduced IL-4 production but increased interferon- gamma production, and inhibited GATA-3 gene expression. RG-II also inhibited asthmatic reactions including an increase in the number of eosinophils in bronchoalveolar lavage fluid, an increase in inflammatory cell infiltration in lung tissues, airway luminal narrowing, and airway hyperresponsiveness. This study provides evidence that RG-II plays a critical role in ameliorating the pathogenic process of asthmatic inflammation in mice. These findings provide new insights into the immunotherapeutic role of RG-II in terms of its effects in a murine model of asthma.

GSTT1 and GSTM1 gene polymorphisms as major risk factors for asthma in a North Indian population

BACKGROUND

According to the National Family Health Survey, asthma is one of the leading diseases in India. In order to understand the complexity of asthma, the susceptibility genes need to be targeted for their association. Glutathione S-transferases play a major role in the detoxification of metabolites of oxidative stress resulting in inflammation and asthma. In the present study, the hypothesis that GSTT1 and GSTM1 gene polymorphisms are associated with asthma was examined.

METHODS

This is the first study to investigate the role of GSTT1 and GSTM1 gene polymorphisms in asthma pathogenesis in a North Indian population. A total of 824 subjects were recruited, of which 410 were asthma patients, including 323 patients suffering from allergic rhinitis. The other 414 recruits were healthy controls from regions of North India. Multiplex PCR was used for genotyping the GSTT1 and GSTM1 gene polymorphisms.

RESULTS

The GSTT1 null allele was more prevalent in asthma patients (40 %) than in the control subjects (13.3 %), which yielded a nearly fourfold risk towards asthma with odds ratio (OR) (95 % CI) = 4.35 (3.04-6.24), χ(2) = 75.34, and p = 0.000. The GSTM1 polymorphism also revealed a greater prevalence of the GSTM1 null allele in asthma patients (46.6 %) than in controls (39.4 %). Statistical analysis yielded a marginal risk toward asthma with OR (95 % CI) = 1.34 (1.01-1.79), χ(2) = 4.37, and p = 0.036.

CONCLUSIONS

Polymorphisms as a result of deletions in the GSTT1 and GSTM1 genes confer an increased risk towards asthma thereby suggesting the protective role of these functional genes in the development of the disease.

Effects of Corni fructus on ovalbumin-induced airway inflammation and airway hyper-responsiveness in a mouse model of allergic asthma

BACKGROUND

Allergic asthma is a chronic inflammatory lung disease that is characterized by airway hyperresponsiveness (AHR) to allergens, airway oedema, increased mucus secretion, excess production of T helper-2 (Th2) cytokines, and eosinophil accumulation in the lungs. Corni fructus (CF) is a fruit of Cornus officinalis Sieb. Et. Zucc. (Cornaceae) and has been used in traditional Korean medicine as an anti-inflammatory, analgesic, and diuretic agent. To investigate the anti-asthmatic effects of CF and their underlying mechanism, we examined the influence of CF on the development of pulmonary eosinophilic inflammation and airway hyperresponsiveness in a mouse model of allergic asthma.

METHODS

In this study, BALB/c mice were systemically sensitized to ovalbumin (OVA) by intraperitoneal (i.p.), intratracheal (i.t.) injections and intranasal (i.n.) inhalation of OVA. We investigated the effect of CF on airway hyperresponsiveness, pulmonary eosinophilic infiltration, various immune cell phenotypes, Th2 cytokine production, and OVA-specific immunoglobulin E (IgE) production.

RESULTS

The CF-treated groups showed suppressed eosinophil infiltration, allergic airway inflammation, and AHR via reduced production of interleuin (IL) -5, IL-13, and OVA-specific IgE.

CONCLUSIONS

Our data suggest that the therapeutic effects of CF in asthma are mediated by reduced production of Th2 cytokines (IL-5), eotaxin, and OVA-specific IgE and reduced eosinophil infiltration.

Upregulated protein arginine methyltransferase 1 by IL-4 increases eotaxin-1 expression in airway epithelial cells and participates in antigen-induced pulmonary inflammation in rats

Protein arginine methyltransferases (PRMTs), catalyzing methylation of both histones and other cellular proteins, have emerged as key regulators of various cellular processes. This study aimed to identify key PRMTs involved in Ag-induced pulmonary inflammation (AIPI), a rat model for asthma, and to explore the role of PRMT1 in the IL-4-induced eosinophil infiltration process. E3 rats were i.p. sensitized with OVA/alum and intranasally challenged with OVA to induce AIPI. The expressions of PRMT1-6, eotaxin-1, and CCR3 in lungs were screened by real-time quantitative PCR. Arginine methyltransferase inhibitor 1 (AMI-1, a pan-PRMT inhibitor) and small interfering RNA-PRMT1 were used to interrupt the function of PRMT1 in A549 cells. In addition, AMI-1 was administrated intranasally to AIPI rats to observe the effects on inflammatory parameters. The results showed that PRMT1 expression was mainly expressed in bronchus and alveolus epithelium and significantly upregulated in lungs from AIPI rats. The inhibition of PRMTs by AMI-1 and the knockdown of PRMT1 expression were able to downregulate the expressions of eotaxin-1 and CCR3 with the IL-4 stimulation in the epithelial cells. Furthermore, AMI-1 administration to AIPI rats can also ameliorate pulmonary inflammation, reduce IL-4 production and humoral immune response, and abrogate eosinophil infiltration into the lungs. In summary, PRMT1 expression is upregulated in AIPI rat lungs and can be stimulated by IL-4. Intervention of PRMT1 activity can abrogate IL-4-dependent eotaxin-1 production to influence the pulmonary inflammation with eosinophil infiltration. The findings may provide experimental evidence that PRMT1 plays an important role in asthma pathogenesis.

Fractional exhaled nitric oxide measurements in rhinitis and asthma in children

Exaled nitric oxide (FeNO) is considered a good noninvasive marker to assess airway inflammation in asthma and allergic rhinitis. In asthma, exhaled NO is very useful to verify adherence to therapy, and to predict upcoming asthma exacerbations. It has been also proposed that adjusting anti-inflammatory drugs guided by the monitoring of exhaled NO, could improve overall asthma control. Other studies showed increased FeNO levels in subjects with allergic rhinitis.

Inhibitory effects of inhaled complex traditional Chinese medicine on early and late asthmatic responses induced by ovalbumin in sensitized guinea pigs

Background

Many formulae of traditional Chinese medicines (TCMs) have been used for antiasthma treatment dating back many centuries. There is evidence to suggest that TCMs are effective as a cure for this allergenic disease administered via gastric tubes in animal studies; however, their efficacy, safety and side effects as an asthmatic therapy are still unclear.

Methods

In this study, guinea pigs sensitized with ovalbumin (OVA) were used as an animal model for asthma challenge, and the sensitization of animals by bronchial reactivity to methacholine (Mch) and the IgE concentration in the serum after OVA challenge were estimated. Complex traditional Chinese herbs (CTCM) were administered to the animals by nebulization, and the leukocytes were evaluated from bronchoalveolar lavage fluid (BALF).

Results

The results showed that inhalation of CTCM could abolish the increased lung resistance (13-fold increase) induced by challenge with OVA in the early asthmatic response (EAR), reducing to as low as baseline (1-fold). Moreover, our results indicated higher IgE levels (range, 78-83 ng/ml) in the serum of sensitized guinea pigs than in the unsensitized controls (0.9 ± 0.256 ng/ml). In addition, increased total leukocytes and higher levels of eosinophils and neutrophils were seen 6 hours after challenge, and the increased inflammatory cells were reduced by treatment with CTCM inhalation. The interleukin-5 (IL-5) level in BALF was also reduced by CTCM.

Conclusion

Our findings indicate a novel method of administering traditional Chinese medicines for asthma treatment in an animal model that may be more effective than traditional methods.

Antiasthmatic effects of Gleditsia sinensis in an ovalbumin-induced murine model of asthma

This study evaluated the antiasthmatic effects of Gleditsia sinensis ethanolic extract (GSEE) and its underlying mechanisms, using an in vivo murine model of asthma. Female BALB/c mice were sensitized, challenged with ovalbumin, and then examined for asthmatic reactions. The results showed that GSEE exerted profound inhibitory effects on the accumulation of eosinophils in the airways and reduced the levels of interleukin (IL)-4 and IL-5 in bronchoalveolar lavage fluid (BALF) and immunoglobulin E (IgE) in BALF and plasma. Gleditsia sinensis ethanolic extract also suppressed the production of reactive oxygen species in BALF and inflammatory infiltration, in a dose-dependent manner, and it inhibited goblet-cell hyperplasia in lung tissue. Thus, GSEE shows antiasthmatic effects in a murine model of allergic asthma, which appeared to be mediated partially by the reduction of oxidative stress and airway inflammation. These results indicate that GSEE could be an effective novel therapeutic agent for the treatment of allergic asthma.

Effect of genetic variation of IL-13 on airway remodeling in bronchial asthma

BACKGROUND

IL-13 is a major stimulator of inflammation and tissue remodeling at sites of Th2 inflammation, and common single-nucleotide polymorphisms in IL13 are associated with allergic phenotypes in several ethnically diverse populations. In particular, IL13Q110 is the non-conservative replacement of a positively charged arginine (R) with a neutral glutamine (Q) at position 110 of IL-13, and as we already know, individuals homozygous for glutamine (Q110/Q110) are strongly associated with asthma and IgE. IL13Q110 has been demonstrated to show that increased allergic inflammation depended on the enhanced IL-13-mediated Th2 effector function. Therefore, we investigated whether Q110/Q110 accelerated the decline in pulmonary function and development of airway remodeling of asthmatic patients in the general population.

METHODS

A total 336 asthmatic subjects living in Japan were recruited, genotyped, and had a pulmonary function test performed on them. To analyze airway inflammation and remodeling, bronchial lavage fluid (BLF) and endobronchial biopsy specimens were examined.

RESULTS

Forced expiratory volume in one second (FEV1), %predicted, forced expiratory volume/forced vital capacity ratio, and forced expiratory flow 25-75%, % predicted were significantly decreased in Q110/Q110 compared to R110/R110, and the decline in FEV1 was increased significantly in Q110/Q110 compared to R110/R110. The concentration of IL-13, IL-23, IL-11, GM-CSF, hyaluronic acid, and CCL8 in BLF were increased in Q110/Q110 compared to R110/R110 and the thickness of the subepithelial layer was thicker.

CONCLUSIONS

Our study demonstrates that Q110/Q110 increases, at least in part, allergic inflammation and the propensity for airway remodeling, thus resulting in low lung function.

Inhibitory effects of casticin on migration of eosinophil and expression of chemokines and adhesion molecules in A549 lung epithelial cells via NF-κB inactivation

ETHNOPHARMACOLOGICAL RELEVANCE

The fruits of Vitex rotundifolia L. have long been used for the treatment of inflammation of the respiratory tract in East Asia.

AIM

To determine if casticin, one of the constituents of Vitex rotundifolia L., has anti-allergic and anti-inflammatory effects in asthma.

MATERIALS AND METHODS

The in vitro anti-inflammatory activity of casticin was studied in A549 human type II-like epithelial lung cells using an eotaxin inhibition assay. Additionally, its effects on eotaxin, regulated on activation normal T cell expressed and secreted (RANTES), vascular cell adhesion molecule (VCAM)-1, and inter-cellular adhesion molecule (ICAM)-1 expression were investigated by real time-polymerase chain reaction (real time-PCR). The inhibition of nuclear factor κB (NF-κB) activity in the presence of casticin was determined by analyzing confocal microscopy images of fluorescence immunocytochemical analysis while the suppression of inhibitory κB (IκB)-α phosphorylation was studied using Western blot analysis. Finally, the inhibitory effect of casticin on eosinophil migration toward prestimulated A549 cell media was measured using the human eosinophilic leukemia cell line.

RESULTS AND DISCUSSION

Casticin significantly suppressed eotaxin production in cytokine activated A549 lung epithelial cells. Casticin also suppressed the mRNA expression levels of eotaxin, RANTES, VCAM-1, and ICAM-1, which subsequently contributed to the inhibition of eosinophil migration. Furthermore, casticin inhibited IκB-α phosphorylation and nuclear translocation of p65 in A549 cells.

CONCLUSION

Casiticin inhibited the eosinophil migration and activity of chemokines and adhesion molecules involved in the inflammatory process of asthma by suppressing the NF-κB pathway. These results suggest that casticin has the potential for use in the treatment of allergic asthma.

T-cell subset regulation in atopy

Presentation of processed allergen by antigen-presenting cells to T-helper (Th) lymphocytes, which is influenced costimulatory signals, cytokines, chemokines, and regulatory T cells (Tregs), determines the development of different types of T-cell immunity. The discovery of Tregs revolutionized the primary concepts of immune regulation interpreted within the framework of a binary Th1/Th2 paradigm. Tregs play a central role in the maintenance of peripheral homeostasis, the establishment of controlled immune responses, and the inhibition of allergen-specific effector cells. Recently, some other T-cell subsets appeared, including Th17 and Th9 cells, which control local tissue inflammation through upregulation of proinflammatory cytokines and chemokines. This review aims to discuss our understanding of the T-cell subset reciprocal interaction in atopy.

Insulin-like growth factor-binding protein-3 (IGFBP-3) blocks the effects of asthma by negatively regulating NF-κB signaling through IGFBP-3R-mediated activation of caspases

Insulin-like growth factor-binding protein-3 (IGFBP-3) is a multifunctional protein known for modulating mitogenic and metabolic actions of IGFs as well as exerting a variety of biological actions not involving IGFs. Here, we show that IGFBP-3 blocks specific physiological consequences of asthma in an IGF-independent manner in vitro and in vivo. IGFBP-3 treatment effectively reduced all physiological manifestations of asthma examined in vivo (airway hyper-responsiveness, cellular and pathological changes in bronchoalveolar lavage fluid and lung tissue, and expression of numerous proinflammatory molecules). These unique IGFBP-3 effects were further confirmed in IGFBP-3-transgenic mice, thus strengthening the notion of IGFBP-3 actions within the respiratory system. Using human epithelial cells, we demonstrated the following: 1) IGFBP-3 blocks TNF-α-induced expression of proinflammatory molecules; 2) IGFBP-3 attenuates the TNF-α-induced migratory response of eosinophils; and 3) IGFBP-3 negatively regulates TNF-α-induced expression of the key NF-κB regulatory molecules IκBα and p65-NF-κB at the post-translational level. We identified that IGFBP-3 degrades IκBα and p65-NF-κB proteins through IGFBP-3 receptor (IGFBP-3R)-mediated activation of caspases thereby inhibiting TNF-α-induced activation of NF-κB signaling cascades. This unique IGFBP-3/IGFBP-3R action was further confirmed by demonstrating complete inhibition of IGFBP-3 action in the presence of caspase inhibitors as well as IGFBP-3R siRNAs. Non-IGF-binding IGFBP-3 mutants further proved the IGF-independent action of IGFBP-3. Our findings indicate that IGFBP-3 inhibits airway inflammation and hyper-responsiveness via an IGF-independent mechanism that involves activation of IGFBP-3R signaling and cross-talk with NF-κB signaling. The IGFBP-3/IGFBP-3R system therefore plays a pivotal role in the pathogenesis of asthma and can serve as a newly identified potential therapeutic target for this debilitating disease.

Antioxidant and antiasthmatic effects of saucerneol D in a mouse model of airway inflammation

Chronic airway inflammation is a hallmark of asthma, which is an immune-based disease. We evaluated the ability of saucerneol D, a tetrahydrofuran-type sesquilignan isolated from Saururus chinensis, to regulate airway inflammation in an ovalbumin (OVA)-induced airway inflammation model. Furthermore, we determined whether heme oxygenase (HO)-1 was required for the protective activity of saucerneol D. The airways of OVA-sensitized mice exposed to an OVA challenge developed eosinophilia and mucus hypersecretion and exhibited increased cytokine levels. Mice were administered saucerneol D orally at doses of 20 and 40mg/kg once daily on days 26-30. Saucerneol D administered orally significantly inhibited the number of OVA-induced inflammatory cells and the production of immunoglobulin E as well as Th2-type cytokines. Histopathology studies revealed a marked decrease in lung inflammation and goblet cell hyperplasia after saucerneol D treatment. In addition, saucerneol D induced HO-1 and led to a marked decrease in OVA-induced reactive oxygen species and malondialdehyde and an increase in superoxide dismutase and glutathione in lung tissues. These antioxidant effects were correlated with HO-1 induction. In our experiments, saucerneol D treatment reduced airway inflammation and suppressed oxidative stress in an OVA-induced asthma model.

Anti-asthmatic effects of Angelica dahurica against ovalbumin-induced airway inflammation via upregulation of heme oxygenase-1

Asthma is a chronic immune inflammatory disease characterized by variable airflow obstruction. The present study was undertaken to assess the effects of an Angelica dahurica Bentham et Hooker ethanolic extract (AD) on airway inflammation in an ovalbumin (OVA)-induced airway inflammation model. Mice that received AD displayed significantly lower airway eosinophilia, cytokine levels, including interleukin (IL)-4, IL-5, and tumor necrosis factor (TNF)-alpha levels, mucus production and immunoglobulin (Ig)E, compared with OVA-induced mice. In our experiments, AD treatment reduced airway inflammation and suppressed oxidative stress in the OVA-induced asthma model, partly via induction of heme oxygenase (HO)-1. The effects of AD on OVA-induced HO-1 induction were partially reversed by the HO-1 inhibitor, tin protoporphyrin (SnPP). Our results clearly indicate that AD is a suppressor of airway allergic inflammation, and may thus be effectively used as an anti-inflammatory drug in the treatment of asthma.

The roles of phytochemicals in bronchial asthma

Despite gaps in our knowledge of how phytochemicals interfere with cellular functions, several natural plant products are utilized to prevent or treat a wide range of diseases. Identification of an agent with therapeutic potential requires multiple steps involving in vitro studies, efficacy and toxicity studies in animal models, and then human clinical trials. This review provides a brief introduction on natural products that may help to treat and/or prevent bronchial asthma and describes our current understanding of their molecular mechanisms based on various in vitro, in vivo, and clinical studies. We focus on the anti-inflammatory and anti-vascular actions of the plant products and other roles beyond the anti-oxidative effects.

Attenuation of allergic airway inflammation and hyperresponsiveness in a murine model of asthma by silver nanoparticles

The use of silver in the past demonstrated the certain antimicrobial activity, though this has been replaced by other treatments. However, nanotechnology has provided a way of producing pure silver nanoparticles, and it shows cytoprotective activities and possible pro-healing properties. But, the mechanism of silver nanoparticles remains unknown. This study was aimed to investigate the effects of silver nanoparticles on bronchial inflammation and hyperresponsiveness. We used ovalbumin (OVA)-inhaled female C57BL/6 mice to evaluate the roles of silver nanoparticles and the related molecular mechanisms in allergic airway disease. In this study with an OVA-induced murine model of allergic airway disease, we found that the increased inflammatory cells, airway hyperresponsiveness, increased levels of IL-4, IL-5, and IL-13, and the increased NF-κB levels in lungs after OVA inhalation were significantly reduced by the administration of silver nanoparticles. In addition, we have also found that the increased intracellular reactive oxygen species (ROS) levels in bronchoalveolar lavage fluid after OVA inhalation were decreased by the administration of silver nanoparticles. These results indicate that silver nanoparticles may attenuate antigen-induced airway inflammation and hyperresponsiveness. And antioxidant effect of silver nanoparticles could be one of the molecular bases in the murine model of asthma. These findings may provide a potential molecular mechanism of silver nanoparticles in preventing or treating asthma.

Neural sensitivity to social rejection is associated with inflammatory responses to social stress

Although stress-induced increases in inflammation have been implicated in several major disorders, including cardiovascular disease and depression, the neurocognitive pathways that underlie inflammatory responses to stress remain largely unknown. To examine these processes, we recruited 124 healthy young adult participants to complete a laboratory-based social stressor while markers of inflammatory activity were obtained from oral fluids. A subset of participants (n = 31) later completed an fMRI session in which their neural responses to social rejection were assessed. As predicted, exposure to the laboratory-based social stressor was associated with significant increases in two markers of inflammatory activity, namely a soluble receptor for tumor necrosis factor-alpha (sTNFalphaRII) and interleukin-6 (IL-6). In the neuroimaging subsample, greater increases in sTNFalphaRII (but not IL-6) were associated with greater activity in the dorsal anterior cingulate cortex and anterior insula, brain regions that have previously been associated with processing rejection-related distress and negative affect. These data thus elucidate a neurocognitive pathway that may be involved in potentiated inflammatory responses to acute social stress. As such, they have implications for understanding how social stressors may promote susceptibility to diseases with an inflammatory component.

Gender differences in transcriptional regulation of IL-5 expression by bronchial lymph node cells in a mouse model of asthma

BACKGROUND AND OBJECTIVE

The severity of asthma after puberty is higher in women than in men. Increased numbers of eosinophils in the airways of female mice after antigen challenge was associated with increased levels of T helper (Th)2 cytokines at the site of inflammation, and in human and mouse studies, the profile of cytokines produced by immune cells from women showed greater Th2 predominance. The aim of this study was to investigate gender differences in the development of Th2 immune responses.

METHODS

Male and female C57BL/6 mice were sensitized with ovalbumin. Cells prepared from bronchial lymph nodes were cultured in the absence or presence of ovalbumin. Cytokine concentrations in the culture supernatants were measured, and IL-5 and GATA-binding protein 3 (GATA-3) gene expression were evaluated. T-cell subsets were analysed using specific surface markers.

RESULTS

The concentrations of IL-4, IL-5, IL-13 and IL-10, but not interferon-gamma or transforming growth factor-beta(1), were higher in cell supernatants from female mice than in those from male mice. IL-5 and GATA-3 gene expressions were higher in cells from women than in cells from men. The numbers of CD3(+)CD4(+)T1/ST2(+) cells, but not CD3(+)CD4(+) or CD4(+)CD25(+) cells, were significantly higher in cells from women than in cells from men.

CONCLUSIONS

Greater antigen-induced Th2 cytokine production by bronchial lymph node cells from female mice was associated with enhanced Th2 cell differentiation and increased expression of the Th2-specific transcription factor, GATA-3.

A new compound, 1H,8H-pyrano[3,4-c]pyran-1,8-dione, suppresses airway epithelial cell inflammatory responses in a murine model of asthma

Clinical and experimental studies have established eosinophilia as a sign of allergic disorders. Activation of eosinophils in the airways is believed to cause epithelial tissue injury, contraction of airway smooth muscle and increased bronchial responsiveness. As part of the search for new antiasthmatic agents produced by medicinal plants, the effects of 270 standardized medicinal plant extracts on cytokine-activated A549 human lung epithelial cells were evaluated. After several rounds of activity-guided screening, the new natural compound, 1H,8H-Pyrano[3,4-c]pyran-1,8-dione (PPY), was isolated from Vitex rotundifolia L. To elucidate the mechanism by which the anti-asthmatic responses of PPY occurred in vitro, lung epithelial cells (A549 cell) were stimulated with TNF-alpha, IL-4 and IL-1beta to induce the expression of chemokines and adhesion molecules involved in eosinophil chemotaxis. PPY treatments reduced the expression of eotaxin, IL-8, IL-16 and VCAM-1 mRNA significantly. Additionally, PPY reduced eotaxin secretion in a dose-dependent manner and significantly inhibited eosinophil migration toward A549 medium. In addition, PPY treatment suppressed the phosphorylation of p65 and ERK1/2, suggesting that it can inhibit the MAPK/NF-KB pathway. To clarify the anti-inflammatory and antiasthmatic effects of PPY in vivo, we examined the influence of PPY on the development of pulmonary eosinophilic inflammation in a murine model of asthma. To accomplish this, mice were sensitized and challenged with ovalbumin (OVA) and then examined for the following typical asthmatic reactions: an increase in the number of eosinophils in BALF; the presence of Th2 cytokines such as IL-4 and IL-5 in the BALF; the presence of allergen-specific IgE in the serum; and a marked influx of inflammatory cells into the lung. Taken together, our results revealed that PPY exerts profound inhibitory effects on the accumulation of eosinophils into the airways while reducing the levels of IL-4, IL-5, and IL-13 in the BALF. Therefore, these results suggest that PPY may be useful as a new therapeutic drug for the treatment of allergic asthma.

Involvement of sirtuin 1 in airway inflammation and hyperresponsiveness of allergic airway disease

BACKGROUND

Bronchial asthma is a chronic inflammatory disorder of the airways characterized by increased expression of multiple inflammatory genes. Acetylation of histones by histone acetyltransferases is associated with increased gene transcription, whereas hypoacetylation induced by histone deacetylases is associated with suppression of gene expression. Sirtuin 1 (SIRT1) is a member of the silent information regulator 2 family that belongs to class III histone deacetylase.

OBJECTIVE

This study aimed to investigate the role of SIRT1 and the related molecular mechanisms in the pathogenesis of allergic airway disease.

METHODS

By using a murine model of ovalbumin (OVA)-induced allergic airway disease and murine tracheal epithelial cells, this study investigated the involvement of SIRT1 and its signaling networks in allergic airway inflammation and hyperresponsiveness.

RESULTS

In this study with mice after inhalation of OVA, the increased levels of SIRT1, hypoxia-inducible factor 1alpha (HIF-1alpha), and vascular endothelial growth factor protein in the lungs after OVA inhalation were decreased substantially by the administration of a SIRT1 inhibitor, sirtinol. We also showed that the administration of sirtinol reduced significantly the increased numbers of inflammatory cells of the airways; airway hyperresponsiveness; increased levels of IL-4, IL-5, and IL-13; and increased vascular permeability in the lungs after OVA inhalation. In addition, we have found that inhibition of SIRT1 reduced OVA-induced upregulation of HIF-1alpha in airway epithelial cells.

CONCLUSIONS

These results indicate that inhibition of SIRT1 might attenuate antigen-induced airway inflammation and hyperresponsiveness through the modulation of vascular endothelial growth factor expression mediated by HIF-1alpha in mice.

Plasminogen activator inhibitor type-1 gene 4G/5G polymorphism in Turkish adult patients with asthma

AIM

This study has been performed on asthmatic patients in the Turkish population to determine the frequency of 4G/5G polymorphism genotypes of plasminogen activator inhibitor type-1 gene, and with the aim of examining the role of this polymorphism in asthma development.

METHODS

Genomic DNA obtained from 165 persons (98 patients with asthma and 67 healthy controls) was used in the study. DNA was multiplied with polymerase chain reaction using 4G and 5G allele-specific primers. Polymerase chain reaction products were assessed with CCD camera by being exposed to 2% agarose gel electrophoresis. Results were evaluated with chi-square test.

RESULTS

No statistically significant difference between the groups with respect to genotype distribution was found (p > 0.05) in the study. The 4G allele frequency was indicated as 48% and 5G allele was as 52% in patients, whereas this was 50-50% in the control group.

CONCLUSION

It has been established by this study that 4G/5G polymorphism genotypes of plasminogen activator inhibitor type-1 gene do not play a role in the development of asthma in the Turkish population.

Inhibitory effects of Schizandrae Fructus on eotaxin secretion in A549 human epithelial cells and eosinophil migration

Eosinophilia have been implicated in a broad range of diseases, most notably allergic conditions (e.g. asthma, rhinitis and atopic dermatitis) and inflammatory diseases. These diseases are characterized by an accumulation of eosinophils in the affected tissue. Defining the mechanisms that control the recruitment of eosinophil is fundamental to understanding how these diseases progress and identifying a novel target for drug therapy. Accordingly, this study was conducted to evaluate the regulatory effect of Schizandrae Fructus (SF) on the expression of eotaxin, an eosinophil-specific chemokine released in respiratory epithelium following allergic stimulation, as well as its effects on eosinophil migration. To accomplish this, human epithelial lung cells (A549 cell) were stimulated with a combination of TNF-alpha (100ng/ml) and IL-4 (100ng/ml) for 24h. The cells were then restimulated with TNF-alpha (100ng/ml) and IL-1beta (10ng/ml) to induce the expression of chemokines and adhesion molecules involved in eosinophil chemotaxis for another 24h. Next, the samples were treated with various concentrations of Schizandrae Fructus (SF) (1, 10, 100, 1000microg/ml) or one of the major constituents of SF, schizandrin (0.1, 1, 10, 100microg/ml), after which following inhibition effect assay was performed triplicates in three independence. The levels of eotaxin in secreted proteins were suppressed significantly by SF (100 and 1000microg/ml, p<0.01) and schizandrin (10 and 100microg/ml, p<0.01). In addition, SF (1, 10, 100 and 1000microg/ml) decreased mRNA expression levels in A549 cells significantly (p<0.01). Eosinophil recruitment to lung epithelial cells was also reduced by SF, which indicates that eotaxin plays a role in eosinophil recruitment. Furthermore, treatment with SF suppressed the expression of another chemokine, IL-8 (0.1 and 1microg/ml SF, p<0.01), as well as intercellular adhesion molecule-1 (10 and 100microg/ml SF, p<0.01) and vascular cell adhesion molecule-1 (0.1 and 1microg/ml SF, p<0.05), which are all related to eosinophil migration. Taken together, these findings indicate that SF may be a desirable medicinal plant for the treatment of allergic diseases.

Eosinophil cationic protein stimulates migration of human lung fibroblasts in vitro

Asthma is characterized by eosinophilic inflammation and remodelling of the airways. Eosinophil cationic protein (ECP) is a protein released by activated eosinophils and the hypothesis that ECP contributes to the development of structural changes in the airways of asthmatics has been posed. Fibroblast recruitment is an important step in the remodelling process, and we therefore put the question whether ECP stimulates migration of human lung fibroblasts. Human peripheral eosinophils isolated from buffycoats from healthy individuals were cultured and conditioned media (CM) were collected. Native ECP was extracted from human peripheral eosinophils by gel filtration, ion-exchange and chelating chromatography. The ability of eosinophil CM and ECP to stimulate fibroblast migration was determined using the 48-well Boyden chamber. ECP concentrations in CM were assayed by ECP-CAP-FEIA. Both CM and ECP significantly stimulated fibroblast migration (48.4+/-cells/field versus 33+/-2 and 36+/-6 versus 25+/-4; P<0.001 and 0.05 respectively) in a time- and concentration-dependent manner. Adding neutralizing ECP antibodies attenuated fibroblast migration induced by both ECP as well as CM. ECP stimulates migration of human lung fibroblasts, suggesting a potential mechanism for eosinophils in the fibrotic response. This may be an important mechanism by which ECP promotes remodelling of extracellular matrix leading to airway fibrosis in asthmatics.

Apigenin protects ovalbumin-induced asthma through the regulation of GATA-3 gene

Apigenin, a dietary plant-flavonoid has shown anti-inflammatory and anticancer properties, however the molecular basis of this effect remains to be elucidated. Thus we elucidated to anti-allergic effect of apigenin in ovalbumin (OVA)-induced asthma model mice. The OVA-induced mice showed allergic airway reactions. It included an increase in the number of eosinophils in bronchoalveolar lavage (BAL) fluid, an increase in inflammatory cell infiltration into the lung around blood vessels and airways, airway luminal narrowing, and the development of airway hyper-responsiveness (AHR). The administration of apigenin before the last airway OVA challenge resulted in a significant inhibition of all asthmatic reactions. Accordingly, this study may provide evidence that apigenin plays a critical role in the amelioration of the pathogenetic process of asthma in mice. These findings provide new insight into the immunopharmacological role of apigenin in terms of its effects in a murine model of asthma.

Quercetin regulates Th1/Th2 balance in a murine model of asthma

Quercetin is found to be the most active of the flavonoids in studies and many medicinal plants owe much of their activity to their high Quercetin content. Quercetin has demonstrated significant anti-inflammatory activity because of direct inhibition of several initial processes of inflammation. However, its anti-allergic effect in the Th1/Th2 immune response was poorly understood. Recently, it was shown that T-bet and GATA-3 were master Th1 and Th2 regulatory transcription factors. In this study, we have attempted to determine whether Quercetin regulates Th1/Th2 cytokine production, T-bet and GATA-3 gene expression in OVA-induced asthma model mice. Quercetin reduced the increased levels of IL-4, Th2 cytokine production in OVA-sensitized and -challenged mice. The other side, it increased IFN-gamma, Th1 cytokine production in Quercetin administrated mice. We also examined to ascertain whether Quercetin could influence Eosinophil peroxidase (EPO) activity. The administration of Quercetin before the last airway OVA challenge resulted in a significant inhibition of all asthmatic reactions. Accordingly, this study may provide evidence that Quercetin plays a critical role in the amelioration of the pathogenetic process of asthma in mice. These findings provide new insight into the immunopharmacological role of Quercetin in terms of its effects in a murine model of asthma, and also broaden current perspectives in our understanding of the immunopharmacological functions of Quercetin.

Anti-asthmatic effect of marine red alga (Laurencia undulata) polyphenolic extracts in a murine model of asthma

The aim of the present work is focused on protective effects of an edible red alga, Laurencia undulata ethanolic (EtOH) extracts (LU) containing a large amount of polyphenols against OVA-induced murine allergic airway reactions using in vivo histological and cytokine assay. Mice sensitized and challenged with ovalbumin (OVA) showed typical asthmatic reactions as follows: an increase in the number of eosinophil in bronchoalveolar lavage fluid; a marked influx of inflammatory cells into the lung around blood vessels and airways, and airway luminal narrowing; the development of airway hyperresponsiveness; the detection of TNF-alpha and Th2 cytokines, such as IL-4 and IL-5 in the bronchoalveolar lavage (BAL) fluid; and detection of allergen-specific IgE in the serum. The successive intraperitoneal administration of LU before the last airway OVA-challenge resulted in a significant inhibition of all asthmatic reactions. These results suggest that L. undulata polyphenolic extracts possess therapeutic potential for combating bronchial asthma associated with allergic diseases.

Nafamostat mesilate, a potent serine protease inhibitor, inhibits airway eosinophilic inflammation and airway epithelial remodeling in a murine model of allergic asthma

To clarify the involvement of serine proteases in the development of allergic airway inflammation, we investigated the effect of nafamostat mesilate, a serine protease inhibitor, in a murine model of allergic asthma. Mice were sensitized to ovalbumin (OA) with alum and then exposed to 1% OA for 30 min, three times every 4th day. Nafamostat mesilate was administered orally for 10 days during the allergen challenge. In sensitized mice, repeated allergen challenge induced an increase in tryptase proteolytic activity in bronchoalveolar lavage fluid (BALF). In addition, marked increases in the numbers of inflammatory cells, levels of T helper type 2 (Th2) cytokines and eotaxin in BALF, numbers of goblet cells in the epithelium, and level of OA-specific IgE in serum were observed after repetitive allergen inhalation. Treatment with nafamostat mesilate significantly inhibited not only increased proteolytic activities, but also increases in the numbers of eosinophils and lymphocytes in the BALF. Nafamostat mesilate also dose-dependently inhibited increases in the levels of interleukin-13 and eotaxin in BALF and goblet cell hyperplasia. These findings suggest that increased serine protease activity in the airways is involved in the development of antigen-induced allergic eosinophilic inflammation and epithelial remodeling in bronchial asthma.

The pros and cons of immunomodulatory IL-10 gene therapy with recombinant AAV in a Cftr-/- -dependent allergy mouse model

Cystic fibrosis (CF) patients have decreased levels of lung epithelial interleukin (IL)-10 and increased levels of proinflammatory cytokines (tumor necrosis factor-alpha, IL-4, IL-8 and IL-6). This has also been documented in Cftr (cystic fibrosis transmembrane conductance regulator)-deficient mice (Cftr 489X(-/-), FABP-hCFTR(+/+)). Our laboratory has recently characterized a peculiar hyper-IgE phenotype in these mice, in response to Aspergillus fumigatus crude protein extract (Af-cpe). Thus, we hypothesized that sustained systemic circulating IL-10 levels achieved through skeletal muscle transduction with recombinant adeno-associated vectors expressing IL-10 (rAAV1-IL-10) would serve to downregulate Th1 and Th2 cytokine production. This in turn would dampen the allergic response in the Cftr(-/-)-dependent mouse model of allergic bronchopulmonary aspergillosis. After Af-cpe sensitization and airway challenge, mice treated with rAAV1-IL-10 had markedly lower IgE levels when compared to the control-treated rAAV1-GFP group. This was accompanied by a significant reduction in the levels of IL-5, IL-4 and IL-13 in the lung compartment. The lower lung cytokine profiles resulted in a near absence of eosinophil recruitment in the lung and a lower inflammatory response in the lung tissue of mice receiving rAAV1-IL-10. Unfortunately, sustained secretion of IL-10 from transduced muscle did lead to thrombocytopenia and splenomegaly in mice injected with rAAV1-IL-10. These results highlight that while IL-10 gene therapy is very effective for treating allergic responses caution must be taken with the prolonged secretion of IL-10.

Curcumin attenuates ovalbumin-induced airway inflammation by regulating nitric oxide

Curcumin has been strongly implicated as an anti-inflammatory agent, but the precise mechanisms of its action are largely unknown. In this study, we show that curcumin contributes to anti-inflammatory activity in the murine asthma model and lung epithelial cell A549 through suppression of nitric oxide (NO). To address this problem, curcumin was injected into the peritoneum of ovalbumin (OVA)-sensitized mice before the last allergen challenge. OVA challenge resulted in activation of the production of inducible nitric oxide (iNOS) in lung tissue, inflammatory cytokines, recruitment of eosinophils to lung airways, and airway hyper-responsiveness to inhaled methacholine. These effects of ovalbumin challenge were all inhibited by pretreatment of mice with curcumin. Furthermore, supplementation with curcumin in the A549 human airway epithelial cells decreased iNOS and NO production induced by IFN-gamma. These findings show that curcumin may be useful as an adjuvant therapy for airway inflammation through suppression of iNOS and NO.

Lycopene suppresses ovalbumin-induced airway inflammation in a murine model of asthma

In this study, we attempt to determine whether lycopene regulates inflammatory mediators in the ovalbumin (OVA)-induced murine asthma model. To address this, mice were sensitized and challenged with OVA, and then treated with lycopene before the last OVA challenge. Administration of lycopene significantly alleviated the OVA-induced airway hyperresponsiveness to inhaled methacholine. Administration of lycopene also resulted in a significant inhibition of the infiltration of inflammatory immunocytes into the bronchoalveolar lavage, and attenuated the gelatinolytic activity of matrix metalloproteinase-9 and the expression of eosinophil peroxidase. Additionally, lycopene reduced the increased levels of GATA-3 mRNA level and IL-4 expression in OVA-challenged mice. However, it increased T-bet mRNA level and IFN-gamma expression in lycopene-challenged mice. These findings provide new insight into the immunopharmacological role of lycopene in terms of its effects in a murine model of asthma.

Effects of radix adenophorae and cyclosporine A on an OVA-induced murine model of asthma by suppressing to T cells activity, eosinophilia, and bronchial hyperresponsiveness

The present study is performed to investigate the inhibitory effects of Radix Adenophorae extract (RAE) on ovalbumin-induced asthma murine model. To study the anti-inflammatory and antiasthmatic effects of RAE, we examined the development of pulmonary eosinophilic inflammation and inhibitory effects of T cells in murine by RAE and cyclosporine A (CsA). We examined determination of airway hyperresponsiveness, flow cytometric analysis (FACS), enzyme-linked immunosorbent assay (ELISA), quantitative real time (PCR), hematoxylin-eosin staining, and Masson trichrome staining in lung tissue, lung weight, total cells, and eosinophil numbers in lung tissue. We demonstrated how RAE suppressed development on inflammation and decreased airway damage.

Airway eosinophilic inflammation is attenuated in conserved noncoding sequence-1-deficient mice

BACKGROUND

Conserved noncoding sequence-1 (CNS-1) is an important regulatory element for T helper 2 cytokine expression. IL-4, IL-5 and IL-13 expression as well as serum IgE level were attenuated in CNS-1-/- mice.

METHOD

CNS-1-/- and CNS-1+/+ mice were sensitized with ovalbumin (OVA) followed by antigen challenge. The number of eosinophils and T helper 2 cytokine concentration in the bronchoalveolar lavage fluid, OVA-specific IgE antibody (Ab) in the serum and bronchial responsiveness to methacholine were examined.

RESULTS

Bronchoalveolar lavage fluid eosinophilia was significantly attenuated in CNS-1-/- mice compared to CNS-1+/+ mice, which were sensitized with OVA/aluminum once. OVA-specific IgE Ab was also attenuated. When mice were sensitized with OVA/aluminum twice, induction of eosinophilia and OVA-specific IgE Ab was not significantly different between CNS-1-/- and CNS-1+/+ mice.

CONCLUSION

CNS-1 locus regulates eosinophilic inflammation in vivo.

A contraction assay system using established human bronchial smooth muscle cells

BACKGROUND

To further understand the mechanisms of airway obstruction in asthma, it is crucial to investigate contractile responses of human airway smooth muscle. An in vitro assay system employing collagen gels embedded with well-established bronchial smooth muscle cells of human origin was explored in the present study.

METHODS

Commercially available cultured human bronchial smooth muscle cells were embedded into a collagen gel. Well-known constrictors, histamine and methacholine, were added to the gel. The gel images were captured by an image analyzer, and contractile responses were evaluated.

RESULTS

Histamine and methacholine induced contraction of the gels in a dose-dependent manner. Pyrilamine, an H1 receptor antagonist, inhibited gel contraction in an agonist-specific manner.

CONCLUSION

Our contraction assay system, employing widely distributed cultured cells, was highly reproducible and precise. It may go a long way toward understanding mechanisms of asthmatic responses and evaluation of antiasthma drugs.

Partial correction of the CFTR-dependent ABPA mouse model with recombinant adeno-associated virus gene transfer of truncated CFTR gene

Recently, we have developed a model of airway inflammation in a CFTR knockout mouse utilizing Aspergillus fumigatus crude protein extract (Af-cpe) to mimic allergic bronchopulmonary aspergillosis (ABPA) 1, an unusual IgE-mediated hypersensitivity syndrome seen in up to 15% of cystic fibrosis (CF) patients and rarely elsewhere. We hypothesized that replacement of CFTR via targeted gene delivery to airway epithelium would correct aberrant epithelial cytokine signaling and ameliorate the ABPA phenotype in CFTR-deficient (CFTR 489X - /-, FABP-hCFTR + / +) mice. CFTR knockout mice underwent intra-tracheal (IT) delivery of recombinant adeno-associated virus serotype 5 (rAAV5Delta-264CFTR) or rAAV5-GFP at 2.58 x 10(12) viral genomes/mouse. All mice were then sensitized with two serial injections (200 microg) of crude Af antigen via the intra-peritoneal (IP) route. Untreated mice were sensitized without virus exposure. Challenges were performed 2 weeks after final sensitization, using a 0.25% solution containing Aspergillus fumigatus crude protein extract delivered by inhalation on three consecutive days. The rAAV5Delta-264CFTR-treated mice had lower total serum IgE levels (172513 ng/ml +/- 1312) than rAAV5-GFP controls (26 892 ng/ml +/- 3715) (p = 0.037) and non-treated, sensitized controls (24 816 +/- 4219 ng/ml). Serum IgG1 levels also were lower in mice receiving the CFTR vector. Interestingly, splenocytes from rAAV5Delta-264CFTR-treated mice secreted less IL-13, INFg, TNFa, RANTES and GM-CSF after ConA stimulation. Gene therapy with rAAV5Delta-264CFTR attenuated the hyper-IgE response in this reproducible CF mouse model of ABPA, with systemic effects also evident in the cytokine response of stimulated splenocytes.

The role of histamine H1 and H4 receptors in allergic inflammation: the search for new antihistamines

Histamine has a key role in allergic inflammatory conditions. The inflammatory responses resulting from the liberation of histamine have long been thought to be mediated by the histamine H1 receptor, and H1-receptor antagonists--commonly known as antihistamines--have been used to treat allergies for many years. However, the importance of histamine in the pathology of conditions such as asthma and chronic pruritus may have been underestimated. Here, we review accumulating evidence suggesting that histamine indeed has roles in inflammation and immune function modulation in such diseases. In particular, the discovery of a fourth histamine receptor (H4) and its expression on numerous immune and inflammatory cells has prompted a re-evaluation of the actions of histamine, suggesting a new potential for H4-receptor antagonists and a possible synergy between H1 and H4-receptor antagonists in targeting various inflammatory conditions.

Glutamine preferentially inhibits T-helper type 2 cell-mediated airway inflammation and late airway hyperresponsiveness through the inhibition of cytosolic phospholipase A(2) activity in a murine asthma model

BACKGROUND

The non-essential amino acid, l-glutamine (Gln), is abundant in the human body. Gln exhibits beneficial effects on endotoxic shock through the inhibition of cytosolic phospholipase A(2) (cPLA(2)) activity. cPLA(2) has been reported to be implicated in the pathogenesis of asthma, but the effects of Gln on asthma have not yet been defined.

OBJECTIVE

To investigate the effects of Gln on allergic bronchial inflammation and airway hyperresponsiveness (AHR), and to determine the possible action mechanisms of Gln in a murine model of asthma.

METHODS

cPLA(2) phosphorylation was assessed by immunoprecipitation and Western blotting. Smears of bronchoalveolar lavage cells were stained with Diff-Quik solution for differential cell counting. Airway levels of the proteins [T-helper type-1 (Th1) and Th2 cytokines, and mucin] were measured by ELISA. mRNA expression of cytokines was assessed by real-time RT-PCR. AHR was assessed as a change in airway resistance (RL). Histological studies were performed to assess the levels of mucin and pulmonary inflammation.

RESULTS

Systemic Gln administration inhibited cPLA(2) phosphorylation and its enzymatic activity in the lungs. Additionally, Gln effectively suppressed the key features of Th2-dependent asthmatic features, such as airway eosinophilia, mucus formation, and airway type 2 cytokine production, as well as late AHR.

CONCLUSION

Gln was found to be effective in the suppression of Th2-dependent phenotypes and late AHR, and this effect of Gln appeared to be at least partially attributable to its ability to suppress cLPA(2) activity in the airway. Our results suggest that clinical use of Gln for patients with asthma may be beneficial.

Inhibition effects of Moutan Cortex Radicis on secretion of eotaxin in A549 human epithelial cells and eosinophil migration

Eosinophils have been implicated in a broad range of diseases, most notably allergic conditions (e.g. asthma, rhinitis and atopic dermatitis) and inflammatory diseases. These diseases are characterized by an accumulation of eosinophils in the tissue. Defining the mechanisms that control eosinophil recruitment is fundamental to understanding how these diseases progress and may identify a novel target for drug therapy. Eotaxin is a potent eosinophil-specific chemokine that is released in the respiratory epithelium after allergic stimulation.

AIM OF THE STUDY

In this study, we determined whether Moutan Cortex Radicis (MCR), a plant extract, effects eotaxin secretion from A549 epithelial cells and eosinophil chemotaxis, and then examined the mechanism involved.

MATERIALS AND METHODS

Prior to assaying MCR's effects, A549 cells were stimulated with tumor necrosis factor-alpha (TNF-alpha), interleukin-4 (IL-4) and IL-1beta to induce expression of chemokines and adhesion molecules involved in eosinophil chemotaxis. In the presence of MCR, eotaxin, regulated on activation in normal T cells expressed and secreted (RANTES), IL-8, IL-16, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) transcripts were quantitated by real-time RT-PCR.

RESULTS

As a result, 0.01, 1, and 100 microg/ml of MCR treatments reduced eotaxin expression significantly and 0.01, 0.1, 1, 10, and 100 microg/ml of MCR reduced significantly eotaxin secretion. In addition, MCR treatment significantly inhibited eosinophil migration toward A549 medium. And 100 microg/ml of MCR suppressed the activated of nuclear factor (NF)-kappaB.

CONCLUSIONS

These findings indicate that suppressed eotaxin secretion by MCR treatment is due to the inhibition of NF-kappaB activation. Therefore, MCR might be of therapeutic value in treating asthma.

Inhibitory effects of suplatast tosilate on the differentiation and function of monocyte-derived dendritic cells from patients with asthma

BACKGROUND

Dendritic cells (DCs) are antigen-presenting cells that efficiently activate T cells.

OBJECTIVE

We examined the effects of suplatast tosilate, which prevents T-helper type 2 responses, on the differentiation and function of monocyte-derived DCs (moDCs).

METHODS

DCs were differentiated in vitro from peripheral monocytes from patients with asthma by the addition of granulocyte macrophage colony-stimulating factor and IL-4 in the presence or absence of suplatast tosilate. Cell surface molecules (CD1a, CD14, CD80, CD83, CD86, HLA-DR) on immature and mature DCs were analysed with flow cytometry, and the secretion of CC chemokine ligand (CCL)17 (thymus and activation-regulated chemokine), IL-12p70, IL-12p40, and IL-10 was measured with an ELISA. We also studied the proliferative responses of allogeneic CD4(+) T cells from healthy subjects to DCs differentiated in the presence of suplatast tosilate. In addition, the production of IFN-gamma and IL-5 by CD4(+) T cells after coculture with untreated DCs or suplatast tosilate-treated DCs was measured with ELISA.

RESULTS

Suplatast tosilate significantly inhibited the expression of CD1a, CD80, and CD86 on immature DCs and of CD1a, CD80, CD83, and CD86 on mature DCs. Suplatast tosilate also significantly inhibited the secretion of CCL17, IL-12p70, and IL-12p40; however, the secretion of IL-10 was not affected. The proliferative responses of allogeneic CD4(+) T cells to suplatast tosilate-treated DCs were suppressed. Moreover, suplatast tosilate-treated DCs had an impaired capacity to stimulate CD4(+) T cells to produce IFN-gamma and IL-5.

CONCLUSION

Suplatast tosilate inhibits the differentiation, maturation, and function of moDCs.

The suppressive effects of YM-58483/BTP-2, a store-operated Ca2+ entry blocker, on inflammatory mediator release in vitro and airway responses in vivo

YM-58483/BTP-2, 4-methyl-4'-[3,5-bis(trifluoromethyl)-1H-pyrazol-1-yl]-1,2,3-thiadiazole-5-carboxanilide, blocks the store-operated Ca2+ entry (SOCE) that mediates the activation of non-excitable cells. This study investigated the pharmacological profile and therapeutic potential of YM-58483 as anti-asthma drug. YM-58483 inhibited DNP antigen-induced histamine release from and leukotrienes (LTs) production in IgE-primed RBL-2H3 cells, a rat basophilic leukemia cell line, with IC50 values of 460 and 310 nM, respectively. Prednisolone did not inhibit either of these responses. YM-58483 also inhibited phytohemagglutinin-P (PHA)-stimulated IL-5 and IL-13 production in human peripheral blood cells with IC50 values of 125 and 148 nM, respectively, which is approximately 5 times less potent than prednisolone. YM-58483 (30 mg/kg, p.o.) significantly suppressed ovalbumin (OVA)-induced bronchoconstriction in OVA-sensitized guinea pigs, whereas prednisolone did not. YM-58483 (3-30 mg/kg, p.o.) and prednisolone (100mg/kg, p.o.) both significantly and completely suppressed airway hyperresponsiveness (AHR) caused by OVA exposure. Since YM-58483 inhibits two major characteristic symptoms of bronchial asthma, namely bronchoconstriction and AHR via the suppression of inflammatory mediator and cytokine production, SOCE inhibition is a potential approach for treatment.

Lower airways inflammation in allergic rhinitics: a comparison with asthmatics and normal controls

BACKGROUND

Allergic rhinitis (AR) and asthma represent a continuum of atopic disease. AR is believed to pre-dispose an individual to asthma. Compared with asthmatics and normal controls, the inflammatory response in the lower airways of rhinitics is not fully elucidated. To test the hypothesis that the inflammatory response in the airways of subjects with AR is at a level intermediate between that in normal controls and asthmatics, we have characterized bronchial inflammation and cytokine mRNA levels in non-asthmatic allergic rhinitics and compared it with subjects with allergic asthma and with normal controls.

METHODS

Endobronchial mucosal biopsies were obtained at bronchoscopy from 14 allergic rhinitics, 16 asthmatics and 21 normal controls. Biopsies were embedded into glycol methacrylate resin for immunohistochemical analysis of cellular inflammation and snap frozen for semi-quantitative PCR analysis of cytokine mRNA levels.

RESULTS

Airway inflammation in rhinitic subjects was characterized by an increase in submucosal eosinophils, mast cells and the mRNA expression of TNF-alpha, at an intermediate level between healthy and asthmatics. In addition, CD3(+) and CD8(+) lymphocytes in the epithelium, the endothelial expression of vascular adhesion molecule-1 and IL-1 beta mRNA were higher in the allergic rhinitics compared with both normal controls and asthmatics, whereas growth-related oncogene alpha-mRNA was decreased in AR compared with both healthy and asthmatics. Airway inflammation in the asthmatic group was characterized by higher numbers of eosinophils and mast cells, together with an increase in TNF-alpha-mRNA compared with both healthy and rhinitics. IFN-gamma mRNA was the highest in normal controls and lowest in the asthmatics.

CONCLUSIONS

In individuals with AR the present data suggest an intermediate state of airway inflammation between that observed in normal individuals and subjects with clinical asthma. It is also indicated that IFN-gamma production by CD8(+) T lymphocytes could be protective against the development of airway hyperresponsiveness. Further work is needed to evaluate this hypothesis.

Involvement of chloride channels in TGF-beta1-induced apoptosis of human bronchial epithelial cells

Widespread damage of airway epithelium and defective epithelial repair are hallmarks of chronic asthma. Growth factors and cytokines spatially and temporally regulate epithelial shedding and repair. Within this context, a key function is exerted by transforming growth factor (TGF)-beta. Recent growing evidence suggests that chloride (Cl(-)) channels are critical to cell apoptosis. We examined the effects of TGF-beta1 on Cl(-) channel expression and activity and its relationship with apoptosis in human bronchial epithelial cells (HBECs). The small interfering RNA (siRNA) approach was used to investigate the potential role of CLC-3, a member of the volume-regulated Cl(-) channel family, in apoptosis of HBECs. TGF-beta1 significantly induced HBEC apoptosis, which paralleled to a significant decrease in the endogenous expression of CLC-3 protein and mRNA transcripts. Outward rectifying and voltage-dependent CLC-3-like Cl(-) currents in HBECs were diminished by TGF-beta1. siRNA for CLC-3 abolished Cl(-) current and enhanced TGF-beta1-induced cell apoptosis. Overexpression of CLC-3 in HBECs inhibited TGF-beta1-induced cell apoptosis. Bcl-2 was also downregulated after TGF-beta stimulation. TGF-beta1-induced cell apoptosis was suppressed in Bcl-2-transfected HBECs. Our data demonstrate that CLC-3-like voltage-gated chloride channels play a critical role in TGF-beta-induced apoptosis of human airway epithelial cells.

Phosphoinositide 3-kinase signalling in lung disease: leucocytes and beyond

The family of lipid kinases termed phosphoinositide-3-kinase (PI3K) is known to contribute at multiple levels to innate and adaptive immune responses, and is hence an attractive target for drug discovery in inflammatory and autoimmune disease, including respiratory diseases. The development of isoform-selective pharmacological inhibitors, targeted gene manipulation and short interfering RNA (siRNA) target validation have facilitated a better understanding of the role that each member of this family of kinases plays in the physiology and pathology of the respiratory system. In this review, we will evaluate the evidence for the roles of specific PI3K isoforms in the lung and airways, and discuss their potential as targets for novel drug therapies.

Proteomic analysis of peripheral T-lymphocytes in patients with asthma

BACKGROUND

Asthma is chronic airway inflammation that occurs together with reversible airway obstruction. T-lymphocytes play an important role in the pathogenesis of asthma. Proteomic technology has rapidly developed in the postgenomic era, and it is now widely accepted as a complementary technology to genetic profiling. We investigated the changes of proteins in T-lymphocytes of asthma patients by using standard proteome technology: two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and a database search.

METHODS

The proteins of CD3+ T-lymphocytes were isolated from whole blood of six steroid-naive asthmatic patients and of six healthy volunteers. 2D-PAGE was performed and the silver-stained protein spots were comparatively analyzed between the asthma and control groups using an image analyzer. Some differentially expressed spots were identified by MALDI-TOF-MS and database search. The messenger RNA expressions of some identified proteins were examined by real-time polymerase chain reaction (RT-PCR).

RESULTS

Thirteen protein spots in the T-lymphocytes of the asthmatic patients were increased and 12 spots were decreased compared to those of the normal subjects. Among the identified proteins, the increased expression of the messenger RNA of phosphodiesterase 4C and thioredoxin-2 and the decreased expression of the messenger RNA of glutathione S-transferase M3 were confirmed by RT-PCR in the asthmatic patients.

CONCLUSIONS

Proteomic examination of the peripheral T-lymphocytes revealed some differentially expressed proteins in the asthmatic patients. The possibility of using the differentially expressed proteins as important biomarkers and therapeutic targets in asthma patients warrants further studies.

Oral beta2-agonist use by preschool children with asthma in East and Central Harlem, New York

Although studies have documented underuse of controller medications and overuse of short-acting inhaled ss(2)-agonist among children with persistent asthma in disadvantaged communities, the persistence of oral ss(2)-agonist use in pediatric practice has not been studied since inhaled short-acting ss(2)-agonists became widespread. We describe medications used to treat asthma among children 3 to 5 years of age at 10 Head Start and other subsidized preschool centers in East and Central Harlem, New York City. We interviewed 149 parents/guardians of children who were identified as having probable asthma based on physician's diagnosis, persistent symptoms, hospitalization, and medication use. We classified 86 of the 149 children (58%) as having current persistent asthma. Only 15 of them (17%) were reported to have used controller medications at least 5 days/week in the last 4 weeks-only 2 of whom used inhaled corticosteroids. By contrast, 53 children (62%) used oral ss(2)-agonist in the last 4 weeks, often (72%) in conjunction with nebulized or inhaled short-acting ss(2)-agonist. Use of oral ss(2)-agonist was associated with more severe symptoms. This study documents the continued widespread use of oral ss(2)-agonist for treatment of children in a low-income community with high prevalence of asthma.