Effects of Diet-Induced Mild Obesity on Airway Hyperreactivity and Lung Inflammation in Mice

Purpose

Obesity has been suggested to be linked to asthma. However, it is not yet known whether obesity directly leads to airway hyperreactivity (AHR) or obesity-induced airway inflammation associated with asthma. We investigated obesity-related changes in adipokines, AHR, and lung inflammation in a murine model of asthma and obesity.

Materials and Methods

We developed mouse models of chronic asthma via ovalbumin (OVA)-challenge and of obesity by feeding a high-fat diet, and then performed the methacholine bronchial provocation test, and real-time PCR for leptin, leptin receptor, adiponectin, adiponectin receptor (adipor1 and 2), vascular endothelial growth factor (VEGF), transforming growth factor (TGF) β, and tumor necrosis factor (TNF) α in lung tissue. We also measured cell counts in bronchoalveolar lavage fluid.

Results

Both obese and lean mice chronically exposed to OVA developed eosinophilic lung inflammation and AHR to methacholine. However, obese mice without OVA challenge did not develop AHR or eosinophilic inflammation in lung tissue. In obese mice, lung mRNA expressions of leptin, leptin receptor, VEGF, TGF, and TNF were enhanced, and adipor1 and 2 expressions were decreased compared to mice in the control group. On the other hand, there were no differences between obese mice with or without OVA challenge.

Conclusion

Diet-induced mild obesity may not augment AHR or eosinophilic lung inflammation in asthma.     

Critical role of interleukin-5 in the development of a mite antigen-induced chronic bronchial asthma model

Objective and design

Asthma is associated with eosinophilic airway inflammation and characterized by enhanced airway sensitivity. Interleukin (IL)-5 plays an important role in the pathogenesis of asthma. The involvement of IL-5 receptor-mediated cellular signals in the pathogenesis of a mite antigen-induced chronic asthma model was investigated.

Subjects

In this study, 48 female C57BL/6J (WT) mice and IL-5 receptor-deficient (IL-5RKO) mice were used.

Treatment

Mite antigen (50 μl) was intranasally administered 13 times to WT and IL-5RKO mice.

Methods

Airway hypersensitivity (Mch PC₂₀₀) and specific antigen exposure tests were performed, and lung tissue, bronchoalveolar lavage fluid (BALF), and blood were collected to investigate the asthma pathology and differences in the local pulmonary levels of cytokines and chemokines.

Results

Airway sensitivity was enhanced and antigen-specific airway resistance was increased in WT mice. In addition, the number of eosinophils and Th2 cytokine levels in the BALF were increased. In contrast, IL-5RKO mice did not acquire the asthma pathology, such as antigen-specific airway resistance and eosinophilic airway inflammation. Mch PC₂₀₀ was significantly correlated with cysteinyl leukotriene levels in WT mice.

Conclusion

These findings suggested that both IL-5 induced eosinophils and cysteinyl leukotrienes are involved in the pathology of this mite antigen-induced chronic asthma model.     

An Inhibitory Role for Sema4A in Antigen-Specific Allergic Asthma

Purpose

The class IV semaphorin Sema4A is critical for efficient T_H1 differentiation and Sema4a ^?/? mice exhibit impaired T_H1 immune responses. However, the role of Sema4A in T_H2 cell-mediated allergic diseases has not been fully studied. The aim of this study was to clarify the regulatory role possessed by Sema4A in mouse models of allergic diseases, particularly allergic asthma.

Methods

Sema4a ^?/? mice on a BALB/c background were examined for the development of allergic diseases. To induce experimental asthma, mice were sensitized with ovalbumin (OVA) followed by intranasal challenges with OVA. After challenge, airway hyperreactivity (AHR) and airway inflammation were evaluated. The role of Sema4A in asthma was examined using Sema4a ^?/? mice and Sema4A-Fc fusion proteins. The direct effects of Sema4A-Fc on antigen-specific effector CD4⁺ T cells were also examined.

Results

A fraction of Sema4a ^?/? BALB/c mice spontaneously developed skin lesions that resembled atopic dermatitis (AD) in humans. Furthermore, AHR, airway inflammation, and T_H2-type immune responses were enhanced in Sema4a ^?/? mice compared to wild type (WT) mice when immunized and challenged with OVA. In vivo systemic administration of Sema4A-Fc during the challenge period ameliorated AHR and lung inflammation and reduced the production of T_H2-type cytokines in WT mice. The inhibitory effects of Sema4A on airway inflammation were also observed in mice deficient in Tim-2, a Sema4A receptor. Finally, we showed that Sema4A-Fc directly inhibited IL-4-producing OVA-specific CD4⁺ T cells.

Conclusion

These results demonstrate that Sema4A plays an inhibitory role in T_H2-type allergic diseases, such as allergic asthma.     

Prevention of allergic airway hyperresponsiveness and remodeling in mice by <Emphasis Type="Italic">Astragaliradix</Emphasis> Antiasthmatic decoction

Background

Astragali radix Antiasthmatic Decoction (AAD), a traditional Chinese medication, is found effective in treating allergic diseases and chronic cough. The purpose of this study is to determine whether this medication could suppress allergen-induced airway hyperresponsiveness (AHR) and remodeling in mice, and its possible mechanisms.

Methods

A mouse model of chronic asthma was used to investigate the effects of AAD on the airway lesions. Mice were sensitized and challenged with ovalbumin (OVA), and the extent of AHR and airway remodeling were characterized. Cells and cytokines in the bronchoalveolar lavage fluid (BALF) were examined.

Results

AAD treatment effectively decreased OVA-induced AHR, eosinophilic airway inflammation, and collagen deposition around the airway. It significantly reduced the levels of IL-13 and TGF-β1, but exerted inconsiderable effect on INF-γ and IL-10.

Conclusions

AAD greatly improves the symptoms of allergic airway remodeling probably through inhibition of Th2 cytokines and TGF-β1.

     

Intranasal challenge with increasing ovalbumin doses differently affects airway hyperresponsiveness and inflammatory cell accumulation in mouse model of asthma

Objective

To investigate whether challenge with increasing allergen doses could differently affect allergen-induced airway hyperresponsiveness (AHR) and inflammatory cell accumulation in mouse model of asthma, providing an experimental model to investigate their relationship.

Material and methods

AHR and accumulation of inflammatory cells in bronchoalveolar lavage fluid (BALF) and into the lungs were compared in ovalbumin-sensitized mice that were challenged intranasally with 2.5, 10, 25 or 100 μg of ovalbumin/mouse.

Results

Both AHR and inflammatory cell accumulation were proportional to the ovalbumin dose used for challenge. However, in group challenged with 10 μg of ovalbumin airway inflammation was present, although allergen-induced AHR was not detected. Additional analysis indicated that neither mucous hyperproduction nor eosinophil degranulation could be correlated to presence of AHR in this model, whereas concentration of interleukin (IL)-13 in BALF was increased only in those groups in which AHR was present.

Conclusions

Altogether, intranasal challenge of mice with increasing allergen doses could serve as a suitable experimental system for investigation of mechanisms by which airway inflammation leads to allergen-induced AHR. Our initial findings are in line with previous reports that dissociate AHR from amount of eosinophil accumulation and imply the role of IL-13 in this process.     

Inhibition of p38 MAPK Reduces Expression of Vascular Endothelial Growth Factor in Allergic Airway Disease

Background

The p38 mitogen-activated protein kinase (MAPK) appears to play an important role in various pathophysiological responses and has been suggested to be involved in many processes considered critical to the inflammatory response and tissue remodeling. Bronchial asthma is a chronic inflammatory disorder of the airway accompanied by increased vascular permeability. Vascular endothelial growth factor (VEGF) is a potent stimulator of bronchial inflammation, airway remodeling, and physiologic dysregulation that augments antigen sensitization and T-helper type 2 cell (Th2)-mediated inflammation in allergic airway diseases. However, there are little data on the relationship between p38 MAPK signaling and VEGF expression in allergic airway disease.

Objective

This study aimed to investigate the role of p38 MAPK on the pathogenesis of allergic airway disease, more specifically in VEGF expression.

Methods

Using ovalbumin (OVA)-inhaled mice and a selective p38 MAPK inhibitor, SB 239063, the involvement of p38 MAPK in allergen-induced VEGF expression in the airway was evaluated.

Results

The increases of phosphorylation of p38 MAPK, VEGF protein expression, and vascular permeability in the lung after OVA inhalation were decreased substantially by the administration of SB 239063. In addition, SB 239063 significantly reduced the increase of Th2 cytokines and OVA-specific IgE. The inhibition of p38 MAPK or VEGF signaling prevented and also decreased the increases in the number of inflammatory cells and airway hyperresponsiveness in OVA-induced allergic airway disease.

Conclusions

These results indicate that inhibition of p38 MAPK may attenuate allergen-induced airway inflammation and vascular leakage through modulation of VEGF expression in mice.     

Effects of Interleukin-9 Blockade on Chronic Airway Inflammation in Murine Asthma Models

Purpose

Asthma is a chronic inflammatory disease of the airways associated with structural changes and airway remodeling. Interleukin (IL)-9 has pleiotropic effects on both inflammatory cells and airway structural cells, which are involved in asthma pathogenesis. We evaluated the effects of IL-9 blockade on chronic airway inflammation.

Methods

Acute airway inflammation was induced in Balb/c mice using aerosolized ovalbumin (OVA), whereas chronic asthma was induced by OVA exposure for 5 weeks with anti-IL-9 or isotype-matched antibody (Ab) treatment during the OVA challenge. Inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted and lung tissues were stained to detect cellular infiltration, mucus deposition, and collagen accumulation. The levels of interferon (IFN)-γ, IL-4, IL-5, IL-9, IL-17, and immunoglobulin E (IgE) in BALF were measured using enzyme linked immunosorbent assays, and profiles of inflammatory cells and subsets of T helper (Th) cells were analyzed using flow cytometry.

Results

IL-9, IL-17, and IFN-γ levels were significantly increased in the chronic group compared to the acute asthma group. However, the number of IL-9-positive cells was not affected, with a decrease in Th17 cells in OVA-challenged caspase-1 knockout mice. Numbers of eosinophils, neutrophils, B cells, mast cells, and Th17 cells decreased after administration of anti-IL-9 Ab. Total IgE, IL-5, IL-9, and IL-17 levels were also lower in the anti-IL-9 group.

Conclusions

Our results suggest that anti-IL-9 Ab treatment inhibits pulmonary infiltration of inflammatory cells and cytokine production, especially IL-17. These results provide a basis for the use of an anti-IL-9 Ab to combat IL-17-mediated airway inflammation.     

Th2 Responses in OVA-Sensitized BALB/c Mice Are Down-Modulated By Mycobacterium bovis BCG Treatment

Objective

This study aimed to determine whether Mycobacterium bovis Bacillus Calmette-Guérin (BCG) treatment can reverse an established allergic airway inflammation in a BALB/c mouse model of ovalbumin (OVA)-induced airway inflammation.

Methods

OVA sensitized BALB/c mice were challenged with aerosolized OVA on days 28 to 30, 34, 41 and 63. Mice were intranasal treated with BCG on days 35 and 42. Twenty-four hours after the last challenge, blood samples were collected to detect anti-OVA immunoglobulin isotypes, and bronchoalveolar lavage (BAL) was harvested for cell count. Additionally, lungs were collected for histological analysis, detection of the eosinophil peroxidase (EPO) activity and measurement of cytokines and CCL11. The expression of CTLA-4, Foxp3 and IL-10 was also determined in lung tissue by flow cytometry.

Results

BCG treatment was able to inhibit an established allergic Th2-response, by decreasing the allergen-induced eosinophilic inflammation, EPO activity, levels of CCL11 and IL-4, serum levels of IgE and IgG1. Mycobacteria treatment increased lung levels of IFN-γ, IL-10 and TGF-β, and expressions of Foxp3 and CTLA-4 in CD4⁺T cells. Additionally, an increased production of IL-10 by CD8⁺ T cells was observed, even though no detectable changes in CD4⁺IL-10⁺ was noticed.

Conclusion

BCG treatment inhibits features of allergic airway inflammation and the results suggest that the mechanism underlying the down-regulatory effects of BCG on OVA-induced airway inflammation appear to be associated with the induction of both Th1 and T regulatory immune responses.     

The Antiasthma Effect of Neonatal BCG Vaccination Does Not Depend on the Th17/Th1 but IL-17/IFN-�� Balance in a BALB/c Mouse Asthma Model

Objective

This study aimed to determine whether the protective effects of the Mycobacterium bovis Bacillus Calmette?CGuérin (BCG) vaccination on allergic asthma are associated with the T helper (Th) 17/Th1 balance in a murine asthma model.

Methods

BALB/c neonates were vaccinated with BCG on the first day after birth, sensitized with ovalbumin, and then challenged with allergen. The resulting airway inflammation and responsiveness were measured. The levels of IL-17 and interferon (IFN)-?? in BALF and ratio of Th17/Th1 were investigated.

Results

We found that although BCG neonatal vaccination inhibited airway hyperresponsiveness and inflammation following allergen challenge in a BALB/c mouse asthma model, reduced levels of Th2 cytokines were not observed. However, BCG neonatal vaccination reduced IL-17 production and increased IFN-?? production in both the bronchoalveolar lavage fluid and the lung lymphocytes in asthmatic mice.

Conclusion

The antiasthma effects of neonatal BCG vaccination reversed the IL-17/IFN-?? imbalance in a murine asthma model but did not depend on modifying the Th17/Th1 balance.     

Short-term roxithromycin treatment attenuates airway inflammation via MAPK/NF-κB activation in a mouse model of allergic asthma

Objective

We investigated whether roxithromycin reduces ovalbumin-specific allergic asthma symptoms in mice, and we further investigated the inhibitory mechanism of roxithromycin in ovalbumin-specific allergic asthma.

Methods

Mice were divided into five groups (n?=?10 for each): control group, roxithromycin-treated groups (5, 20 and 40?mg/kg) and ovalbumin-challenged group. We measured the recruitment of inflammatory cells into the bronchoalveolar lavage fluid (BALF) or the lung tissues by Kwik-Diff and hematoxylin and eosin (H&;E) staining, goblet cell hyperplasia by alcian blue–periodic acid–Schiff (AB-PAS) staining, airway hyperresponsiveness (AHR) by whole-body plethysmograph chamber, cytokine and immunoglobulin E (IgE) levels by ELISA, and the activation of mitogen-activated protein (MAP) kinases and nuclear factor-kappa B (NF-κB) in the lung tissues by Western blotting.

Results

Treatment with roxithromycin resulted in fewer inflammatory cells in the BALF and peribronchial areas, and decreased AHR, goblet cell hyperplasia, IgE levels and inflammatory cytokines, as well as MAP kinases and NF-κB activation, which are increased in lung tissues of mice with ovalbumin-induced allergic asthma.

Conclusions

Our data suggest that oral administration of roxithromycin suppresses ovalbumin-induced airway inflammation and AHR by regulating the inflammatory cytokines via MAP kinases/NF-κB pathway in inflammatory cells. Based on these results, we suggest that roxithromycin may be used as a therapeutic agent for allergy-induced asthma.     

Establishment and characterization of a murine model for allergic asthma using allergen-specific IgE monoclonal antibody to study pathological roles of IgE

Allergen-specific IgE has long been regarded as a major molecular component of allergic asthma. Although IgE plays a central role in the early asthmatic response, its roles in the chronic phase, such as the late asthmatic response, airway hyperresponsiveness (AHR), and airway remodeling (goblet cell hyperplasia and subepithelial fibrosis) have not yet been defined well. In this study, we investigated the hypothesis that chronic responses could be induced by IgE-dependent mechanisms. BALB/c mice passively sensitized with an ovalbumin (OVA)-specific IgE monoclonal antibody (mAb) were repeatedly challenged with intratracheal administration of OVA. The first challenge induced early phase airway narrowing without any late response, but the fourth challenge caused not only an early but also a late phase response, AHR, and goblet cell hyperplasia. Macrophages, lymphocytes and neutrophils, but not eosinophils, were significantly increased in the lung 24 h after the fourth challenge. Interestingly, levels of OVA-specific IgG1 in serum increased by multiple antigen challenges. A C3a receptor antagonist inhibited the late asthmatic response, AHR, and infiltration by neutrophils. In contrast, no late response, goblet cell hyperplasia, inflammatory cells, or production of IgG1 was observed in severe combined immunodeficient mice. On the other hand, seven challenges in BALB/c mice induced subepithelial fibrosis associated with infiltration by eosinophils. In conclusion, the allergic asthmatic responses induced by passive sensitization with IgE mAb can provide a useful model system to study the pathological roles of IgE in acute and chronic phases of allergic asthma.     

Administration of Pigment Epithelium-Derived Factor Inhibits Airway Inflammation and Remodeling in Chronic OVA-Induced Mice via VEGF Suppression

Purpose

Pigment epithelium-derived factor (PEDF) is a recently discovered antiangiogenesis protein. PEDF possesses powerful anti-inflammatory, antioxidative, antiangiogenic, and antifibrosis properties. It has been reported that PEDF can regulate vascular endothelial growth factor (VEGF) expression. This study aimed to evaluate whether recombinant PEDF protein could attenuate allergic airway inflammation and airway remodeling via the negative regulation of VEGF using a murine model of chronic ovalbumin (OVA)-induced asthma and BEAS-2B human bronchial epithelial cells.

Methods

In an in vivo experiment, mice sensitized with OVA were chronically airway challenged with aerosolized 1% OVA solution for 8 weeks. Treated mice were given injections of recombinant PEDF protein (50 or 100 µg/kg body weight) via the tail vein. In an in vitro experiment, we investigated the effects of recombinant PEDF protein on VEGF release levels in BEAS-2B cells stimulated with IL-1β.

Results

Recombinant PEDF protein significantly inhibited eosinophilic airway inflammation, airway hyperresponsiveness, and airway remodeling, including goblet cell hyperplasia, subepithelial collagen deposition, and airway smooth muscle hypertrophy. In addition, recombinant PEDF protein suppressed the enhanced expression of VEGF protein in lung tissue and bronchoalveolar lavage fluid (BALF) in OVA-challenged chronically allergic mice. In the in vitro experiment, VEGF expression was increased after IL-1β stimulation. Pretreatment with 50 and 100 ng/mL of recombinant PEDF protein significantly attenuated the increase in VEGF release levels in a concentration-dependent manner in BEAS-2B cells stimulated by IL-1β.

Conclusions

These results suggest that recombinant PEDF protein may abolish the development of characteristic features of chronic allergic asthma via VEGF suppression, providing a potential treatment option for chronic airway inflammation diseases such as asthma.     

Effect of ageing on pulmonary inflammation, airway hyperresponsiveness and T and B cell responses in antigen-sensitized and -challenged mice

BACKGROUND: The effect of ageing on several pathologic features of allergic asthma (pulmonary inflammation, eosinophilia, mucus hypersecretion), and their relationship with airway hyperresponsiveness (AHR) is not well characterized. OBJECTIVE: To evaluate lung inflammation, mucus metaplasia and AHR in relationship with age in murine models of allergic asthma comparing young and older mice. METHODS: Young (6 weeks) and older (6, 12, 18 months) BALB/c mice were sensitized and challenged with ovalbumin (OVA). AHR and bronchoalveolar fluid (BALF), total inflammatory cell count and differential were measured. To evaluate mucus metaplasia, quantitative PCR for the major airway mucin-associated gene, MUC-5AC, from lung tissue was measured, and lung tissue sections stained with periodic acid-Schiff (PAS) for goblet-cell enumeration. Lung tissue cytokine gene expression was determined by quantitative PCR, and systemic cytokine protein levels by ELISA from spleen-cell cultures. Antigen-specific serum IgE was determined by ELISA. RESULTS: AHR developed in both aged and young OVA-sensitized/challenged mice (OVA mice), and was more significantly increased in young OVA mice than in aged OVA mice. However, BALF eosinophil numbers were significantly higher, and lung histology showed greater inflammation in aged OVA mice than in young OVA mice. MUC-5AC expression and numbers of PAS+ staining bronchial epithelial cells were significantly increased in the aged OVA mice. All aged OVA mice had increased IL-5 and IFN-gamma mRNA expression in the lung and IL-5 and IFN-gamma protein levels from spleen cell cultures compared with young OVA mice. OVA-IgE was elevated to a greater extent in aged OVA mice. CONCLUSIONS: Although pulmonary inflammation and mucus metaplasia after antigen sensitization/challenge occurred to a greater degree in older mice, the increase in AHR was significantly less compared with younger OVA mice. Antigen treatment produced a unique cytokine profile in older mice (elevated IFN-gamma and IL-5) compared with young mice (elevated IL-4 and IL-13). Thus, the airway response to inflammation is lessened in ageing animals, and may represent age-associated events leading to different phenotypes in response to antigen provocation.     

Elevated Complement Factor H Levels in Asthmatic Sputa

Background

The alternative pathway of the complement system is known to play a role in the generation of asthmatic airway inflammation, but its regulatory complement protein, factor H has not been investigated in this disease.

Purpose

Our aim was to determine the local bronchial complement factor H (CFH) levels in asthma, and to investigate its relationship with complement activation, systemic CFH concentrations and clinical characteristics of patients.

Methods

Induced sputum and plasma were collected from 21 healthy and 26 asthmatic subjects, and complement factor H and SC5b-9 concentrations were assessed by ELISA. Total protein concentrations were determined by biuret-reaction based microassay system from induced sputa.

Results

CFH was detectable in 81 % of healthy and 100 % of asthmatic subjects, while SC5b-9 exceeded the detection limit in 62 % of healthy subjects and 85 % of asthmatic patients. Sputum CFH concentrations and CFH/protein ratios were increased in samples from asthmatic patients, and correlated with loss of lung function, asthma control, severity and medication intensity, but not with plasma CFH concentrations. Sputum CFH/protein ratios were in positive correlation also with sputum eosinophilic cell counts in asthma. SC5b-9 concentrations were not higher in the asthmatic sputa, although they correlated with sputum CFH concentrations.

Conclusions

CFH level is elevated on asthmatic airway surface, and may be associated with uncontrolled inflammation in asthma.     

Fungal immunomodulatory protein-fve could modulate airway remodel through by affect IL17 cytokine

Background

Asthma is one of the most common allergic diseases. Our previous studies have reported that FIP-fve in acute allergic mouse model can reduce inflammation, improve the balance of the Th1/Th2 system. However, the effects of reducing airway remodeling on FIP-fve is still unknown.

Oral Lovastatin Attenuates Airway Inflammation and Mucus Secretion in Ovalbumin-Induced Murine Model of Asthma

Purpose

Lovastatin is an effective inhibitor of cholesterol synthesis. A previous study demonstrated that lovastatin can also suppress airway hyperresponsiveness (AHR) in murine model of asthma. We aimed to investigate the effect of lovastatin on mucus secretion and inflammation-associated gene expression in the lungs of murine model of asthma.

Methods

Female BALB/c mice were sensitized and challenged with ovalbumin (OVA) by intraperitoneal injection, and orally administered lovastatin from days 14 to 27 post-injection. Gene expression in lung tissues was analyzed using real-time polymerase chain reaction. AHR and goblet cell hyperplasia were also examined. BEAS-2B human bronchial epithelial cells were used to evaluate the effect of lovastatin on the expression of cell adhesion molecules, chemokines, and proinflammatory cytokines in vitro.

Results

We showed that lovastatin inhibits the expression of Th2-associated genes, including eotaxins and adhesion molecules, in the lungs of murine model of asthma. Mucin 5AC expression, eosinophil infiltration and goblet cell hyperplasia were significantly decreased in the lung tissue of murine model of asthma treated with lovastatin. Furthermore, lovastatin inhibited AHR and expression of Th2-associated cytokines in bronchoalveolar lavage fluid. However, a high dose (40 mg/kg) of lovastatin was required to decrease specific IgE to OVA levels in serum, and suppress the expression of Th2-associated cytokines in splenocytes. Activated BEAS-2B cells treated with lovastatin exhibited reduced IL-6, eotaxins (CCL11 and CCL24), and intercellular adhesion molecule-1 protein expression. Consistent with this, lovastatin also suppressed the ability of HL-60 cells to adhere to inflammatory BEAS-2B cells.

Conclusions

These data suggest that lovastatin suppresses mucus secretion and airway inflammation by inhibiting the production of eotaxins and Th2 cytokines in murine model of asthma.     

Fractionated irradiations lead to chronic allergic airway inflammation through increasing the influx of macrophages

Objective

In our previous study, repeated irradiations showed persistent depression of immune response, especially Th1-related immune response. Here, we hypothesized and determined that irradiation may exacerbate development of allergic airway inflammation.

Methods

C57BL/6 mice were irradiated repeatedly at 1 Gy or 0.5 Gy. At 6 months after irradiation, mice were sensitized and challenged short-term with OVA. Antigen-specific immunoglobulins, the percentages of inflammatory cells, chemokine expression, cytokine levels, and collagen deposition were tested.

Results

In irradiated mice, IgG2a in serum was lower when compared with that of control mice, while IgG1 was significantly higher. Interestingly, the percentages of macrophages in bronchoalveolar lavage fluid (BALF) and the lung of irradiated mice were significantly higher. Conversely, the percentages of neutrophil were significantly lower in BALF of irradiated mice. In the lung of irradiated mice, MCP-1 and IP-10 for attraction of macrophages showed the higher expression level, but KC expression for neutrophils showed no difference. Next, TGF-β1 and IL-17A in BALF were higher in irradiated mice. In addition, phosphorylated-Smad2/3 was increased in irradiated mice. Finally, the deposition of collagen was increased in irradiated mice.

Conclusion

Our study showed that fractionated irradiation lead to the chronic allergic airway inflammation through increasing the influx of macrophages and active TGF-β levels.     

Receptor Interacting Protein 2 (RIP2) Is Dispensable for OVA-Induced Airway Inflammation in Mice

Purpose

Asthma is a pulmonary chronic inflammatory disease characterized by airway obstruction and hyperresponsiveness. Pattern recognition receptors are known to play a key role in the development of allergic diseases as well as host defenses against microbial infection. Receptor interacting protein 2 (RIP2), a serine/threonine kinase, is an adaptor molecule of NOD1 and NOD2, and genetic variation in this receptor is known to be associated with the severity of allergic asthma in children. In this study, we examined the role of RIP2 in the development of allergic airway inflammation in a mouse model.

Methods

Airway inflammation was induced in mice through intranasal administration of ovalbumin (OVA) after 2 intraperitoneal immunizations with OVA. Lung inflammation and mucus hypersecretion were examined histologically and total cell infiltration in bronchoalveolar (BAL) fluids was determined. Levels of the Th2-related cytokines, IL-5 and IL-13, in lung extracts were measured by ELISA. Serum antigen-specific IgE and IgG1 levels were also assessed.

Results

OVA-induced lung inflammation and mucus hypersecretion were not different between WT and RIP2-deficient mice. The IL-5 and IL-13 levels in the bronchoalveolar (BAL) fluids were also not impaired in RIP2-deficient mice compared to WT mice. Moreover, RIP2 deficiency did not affect serum OVA-specific IgG1 and IgE levels.

Conclusions

Our results suggest that RIP2 is not associated with the development of allergic airway inflammation.     

A water extract of Samchulkunbi-tang attenuates airway inflammation by inhibiting inos and MMP-9 activities in an ovalbumin-induced murine asthma model

Background

In this study, we investigated the effect of Samchulkunbi-tang water extract (SCTE) in an established mouse model of ovalbumin (OVA)-induced allergic asthma. The effects of SCTE on the production of Th1 and Th2 cytokines, eotaxin, and total and OVA-specific immunoglobulin E, inducible nitric oxide synthase expression, and matrix metalloproteinase-9 activity were measured.

Methods

Mice were sensitized on days 0 and 14 with an intraperitoneal injection of 20 μg ovalbumin (OVA) emulsified in 2 mg aluminum hydroxide in 200 μL PBS buffer. On days 21, 22, and 23, mice received an airway exposure to OVA (1%, w/v, in PBS) for 1 h. SCTE was administered orally to mice at doses of 200 and 400 mg/kg per day from days 18 to 23.

Results

SCTE reduced the number of inflammatory cells, cytokines, and chemokines in bronchoalveolar lavage fluids and iNOS expression and MMP-9 activity in mouse lung tissue. Histological studies using hematoxylin & eosin and periodic acid-schiff staining showed that SCTE substantially inhibited OVA-induced inflammatory cell infiltration in lung tissue and goblet cell hyperplasia in the airway. SCTE also reduced IL-4 and IL-13 expression in concanavalin-A-stimulated splenocytes. These results were similar to those obtained with montelukast as a positive control.

Conclusions

Collectively, these results suggest that SCTE may be an effective oral treatment for allergic airway inflammation by virtue of its anti-inflammatory activity.