Short-term cigarette smoke exposure enhances allergic airway inflammation in mice

RATIONALE: Epidemiologic studies suggest that tobacco smoke contributes to the prevalence and occurrence of exacerbations in asthma. The effect of active smoking in adolescents with atopy is poorly understood. OBJECTIVES: We developed an experimental model to investigate the influence of smoking on antigen-induced airway inflammation and airway responsiveness in mice that were previously sensitized. METHODS: Ovalbumin (OVA)-sensitized BALB/c mice were exposed to air or mainstream smoke (5 days/week) and to phosphate-buffered saline (PBS) or OVA aerosol (3 times/week) for 2 weeks (n = 8 for each group). RESULTS: Airway responsiveness to intravenously injected carbachol was increased (p < 0.05) in smoke- and OVA-exposed mice compared with all other groups. There was an additive effect of smoke and OVA exposure on total cell numbers, macrophages, and dendritic cells in bronchoalveolar lavage fluid and on CD4+ and CD8+ T lymphocytes and dendritic cells in lung tissue (p < 0.05 compared with mice exposed to smoke and PBS and to mice exposed to air and OVA). Concurrent smoke and OVA exposure augmented OVA-specific IgE in serum compared with air and OVA exposure. In lavage fluid supernatant, eotaxin was increased in air- and OVA-exposed mice. The further increase observed in the group exposed to both OVA and cigarette smoke came close to formal significance (p = 0.06). Thymus- and activation-regulated chemokine was augmented in mice exposed to either smoke or OVA, without additional effect. CONCLUSIONS: Our data indicate that acute concurrent exposure to allergen and mainstream cigarette smoke enhances airway inflammation and airway responsiveness in previously sensitized mice.     

Uteroglobin-related protein 1 expression suppresses allergic airway inflammation in mice

RATIONALE: Uteroglobin-related protein (UGRP) 1, which is highly expressed in the epithelial cells of the airways, has been suggested to play a role in lung inflammation. OBJECTIVES: The aim of study was to understand the effect of overexpressed UGRP1 on lung inflammation in a mouse model of allergic airway inflammation. METHODS: Ovalbumin-sensitized and -challenged mice, a model for allergic airway inflammation, were used in conjunction with recombinant adenovirus expressing UGRP1. MEASUREMENTS AND MAIN RESULTS: We demonstrated that intranasal administration of adeno-UGRP1 successfully delivered UGRP1 to the epithelial cells of airways and markedly reduced the number of infiltrating inflammatory cells, particularly eosinophils, in lung tissue as well as the level of proinflammatory cytokines such as interleukin (IL)-4, IL-5, and IL-13 in bronchoalveolar lavage fluids. The healed phase of inflammation was clearly seen in the peripheral areas of adeno-UGRP1-treated mouse lungs. CONCLUSION: These results demonstrate that UGRP1 can suppress inflammation in the mouse model of allergic airway inflammation. Based on this result, we propose UGRP1 as a novel therapeutic candidate for treating lung inflammation such as is found in asthma.     

Eosinophil peroxidase mediates protein nitration in allergic airway inflammation in mice.

The eosinophilic inflammatory response in asthma is associated with protein nitration, detected as immunostaining for 3-nitrotyrosine (3NT). As the presence of 3NT is strongly correlated with upregulation of the inducible form of nitric oxide synthase (NOS II), it has been hypothesized that 3NT formation results from the action of peroxynitrite (ONOO-), a highly reactive NO derivative produced from the reaction of molecular NO and O2-. However, recent observations have suggested that the action of peroxidases, including eosinophil peroxidase (EPO), may be responsible for protein nitration. In this study, we used murine models of allergic asthma to address the relative contribution of EPO and NOS II to protein nitration. We studied EPO-deficient New Zealand White (NZW) mice, which were sensitized and challenged intranasally with ovalbumin (OVA). Despite comparable levels of eosinophilia, NO, and superoxide production, NZW mice exhibited markedly decreased 3NT staining around the airways after OVA challenge when compared with two other strains (A/J and C57BL/6J). Immunocytochemical analysis of bronchoalveolar lavage (BAL) cells and lung sections suggested that 3NT staining was largely confined to eosinophils. This was confirmed by Western Blot analysis of proteins from different subsets of BAL cells that demonstrated a marked decrease in 3NT formation in eosinophils from NZW mice. These results contrast with those obtained in OVA-sensitized and -challenged NOS II deficient mice, which despite decreased NO production, exhibited similar 3NT staining in the airways after OVA challenge as in wild-type control mice. In this model, protein nitration was thus not a function of NO production by NOS II. We conclude that in the mouse, 3NT formation after specific allergen challenge is dependent on EPO activity, particularly in eosinophils themselves. In contrast, 3NT formation is not driven by upregulation of NOS II expression in this model and does not appear to depend on increases in the level of NO production.     

Purified aged garlic extract modulates allergic airway inflammation in BALB/c mice

Garlic is known as a potent spice and a medicinal herb with broad therapeutic properties ranging from antibacterial to anticancer and anticoagulant. Our previous studies have shown some immunoregulatory effects for aged garlic extract, suggesting a key role for 14-kD glycoprotein of garlic in shifting the cytokine pattern to T helper-1. In present study, we investigated the effect of 1, 2, and 3 times intraperitoneal injections of aged garlic extract on an established allergic airway inflammation in murine model (BALB/c mice). The garlic extract, isolated by biochemical method, includes proteins precipitation by ammonium sulfate. After injection of the aged garlic extract, IFN-, anti allergen specific IgE and IgG1 were measured in lavage and serum by ELISA and histological assessment was performed on the lung tissues. The results indicated that three-time intra peritoneal injections of the aged garlic extract caused a significant decrease in the hallmark criteria of allergic airway inflammation levels which included eosinophil percentage in lavage, peribronchial lung eosinophils, IgG1 level in lavage and serum, mucous producing goblet cells grade and peribronchial and perivascular inflammation. Our findings in the present research suggested that aged garlic extract has the potential of attenuation of inflammatory features of allergic airway inflammation in murine model.     

白介素25与变态反应性气道炎症

白介素25（Interleukin-25,IL-25）是IL-17家族的成员之一,能诱导嗜酸粒细胞释放IL-6、IL-8、MCP-1、MIP-1等趋化因子,刺激非T/非B细胞释放IL-4、IL-5、IL-13等细胞因子,介导Th2型变态反应,在变态反应性气道炎症中起重要作用。本文就此作一综述。     

Influence of lipopolysaccharide exposure on airway function and allergic responses in developing mice

Exposure to endotoxin has been associated with an exacerbation of asthmatic responses in humans and animal models. However, recent evidence suggests that microbial exposure in early life may protect from the development of asthma and atopy. In this study, we sought to evaluate the effects of lipopolysaccaride (LPS) on airway function in developing mice. In addition, we evaluated the influence of LPS on subsequent allergen sensitization and challenge. Under light anesthesia, 2-3-week-old Balb/c mice received a single intranasal instillation of LPS or sterile physiologic saline. Measurements of airway function were obtained in unrestrained animals, using whole-body plethysmography. Airway responsiveness was expressed in terms of % enhanced pause (Penh) increase from baseline to aerosolized methacholine (Mch). In additional studies, we assessed the functional and cellular responses to ovalbumin sensitization and challenge following prior exposure to LPS.We found that exposure to LPS induced transient airway hyperresponsiveness to Mch. These functional changes were associated with the recruitment of neutrophils and lymphocytes into the bronchoalveolar lavage (BAL) fluid. Airway responsiveness after allergen sensitization and challenge was decreased by prior exposure to LPS. The analysis of BAL cells and cytokines (interferon-gamma and interleukin-4) did not reveal alterations in the overall Th1/Th2 balance.Our findings suggest that LPS leads to airway hyperresponsiveness in developing mice, and may protect against the development of allergen-driven airway dysfunction.     

兴安杜鹃挥发油抗气道变应性炎症的研究

目的 探讨兴安杜鹃挥发油对小鼠气道变应性炎症的治疗。方法 对昆明小鼠采用超声雾化吸入１％卵清蛋白生理盐水致敏,建立小鼠气道变应性炎症模型,检测并比较各组间肺组胺浓度及肺组织病理学变化。结果 治疗组模型组肺组胺浓度差异显著（Ｐ〈０．０５）,肺组织病理学变化表明,治疗组模型组有明显恢复,与正常对照组接近。结论 兴安杜鹃挥发油具有明显的抗炎、平喘作用。     

DNA fragmentation in developing lung fibroblasts exposed to Stachybotrys chartarum (atra) toxins

Stachybotrys chartarum (atra) is a toxic mold that grows on water-damaged cellulose-based materials. Research has revealed also that inhalation of S. chartarum spores caused marked changes in respiratory epithelium, especially to developing lungs. We analyzed the epigenetic potential of S. chartarum spore toxins on developing rat lung fibroblasts using single cell gel electrophoresis (comet assay). Isolated fetal lung fibroblasts were exposed to S. chartarum spore toxins for 15 min, 3, 14, or 24 hr and control cells were exposed to saline under the same conditions. Cells were embedded in agarose, electrophoresed under alkaline conditions and silver stained. DNA damage was assessed in terms of fragmentation as measured by comet tail length (DNA migration) and intensity (% DNA contained within head and tail). Upon visual inspection, control fibroblasts showed no DNA fragmentation whereas S. chartarum-treated cells had definable comets of various degrees depending upon the time-course. Analyses of the comets revealed that exposure to S. chartarum spore toxins for at least 15 min to 14 hr, induced increased DNA fragmentation in a time-dependent manner. The fact that exposure to toxins for 24 hr showed less damage suggested that developing lung fibroblasts may have the capability of repairing DNA fragmentation.     

Residual oil fly ash amplifies allergic cytokines, airway responsiveness, and inflammation in mice

Particulate matter (PM) air pollution may increase symptom severity in allergic asthmatics. To examine possible interaction, or greater than additive responses, between PM effects and allergic responses, an ovalbumin-sensitized and challenged (OVA) mouse model of allergic airways disease was utilized. After challenge, mice were intratracheally instilled with saline vehicle or 3 mg/kg (approximately 60 microg) residual oil fly ash (ROFA), a transition metal-rich emission source PM sample. Physiological and inflammatory responses were examined 1, 3, 8, and 15 d later. In response to intravenously administered methacholine, ROFA increased total respiratory system resistance and decreased compliance 1 d after exposure, whereas effects of OVA lasted at least 15 d after exposure. Significant interactions between OVA and ROFA were mainly observed 8 d after challenge and exposure, especially with respect to compliance. A strong interaction (p < 0.01) between OVA and ROFA exposure resulted in 8-fold (1 d) and 3-fold (3 d) increases in bronchoalveolar lavage (BAL) fluid eosinophil numbers. A similarly strong interaction (8-fold) was observed in BAL fluid interleukin-4 (IL-4) 1 d after challenge and exposure. Significant though less strong interactions were also found with respect to IL-4 and IL-5 by 3 d postchallenge/exposure. This study shows that allergen challenge and exposure to emission source particulate matter containing relatively high levels of transitions metals can interact to increase Th2 cytokine production, eosinophil recruitment, and airway hyperresponsiveness in previously sensitized mice.     

Bioimpedance monitoring of airway inflammation in asthmatic allergic children

BackgroundAsthma in childhood is characterized by chronic inflammation. Measurement of bioimpedance (BI) is a non-invasive way of detecting airway inflammation. The aim was to compare BI with exhaled nitric oxide (eNO) and lung function evaluations in asthmatic allergic children while not exposed to offending allergens.Methods22 asthmatic children allergic to house dust mites have been enrolled while residents at high altitude in an environment free of house dust mites. They were evaluated at T0 after allergen exposure at home, at T1 and at T2 after 1 and 4 months of allergen avoidance, respectively.ResultseNO decreased from 32.21 ± 5.70 ppb at T0 to 21.92 ± 4.36 ppb at T1, after one month at high altitude (p = 0.038), without a further decrease at T2. Data in electrical activity showed a significant decrease in conductivity of lower airways between T0 (48.53 ± 3.53 μA) and T1 (42.08 ± 3.47 μA) (p = 0.023). ΔB parameter (difference between conductivity of lower respiratory tract and average yield) showed significant decrease from T0 (20.75 ± 2.64 μA), and T1 (12.84 ± 2.52 μA) (p < 0.01), but no further decrease at T2. No difference in lung function parameters was observed.ConclusionAllergen avoidance regimen modifies inflammatory parameters in allergic asthmatics. Evaluation of extracellular bioelectrical conductivity seems to represent a promising non-invasive method to assess airway inflammation.     

Increased levels of hypoxia-sensitive proteins in allergic airway inflammation

In this study we investigated the alterations in protein levels that are induced by allergic eosinophilic lung inflammation. Lung tissue eosinophilia and sequestration of inflammatory cells in airspaces were provoked by systemic sensitization with ovalbumin followed by repeated inhalation challenge with aerosolized ovalbumin. Proteome alterations in lung tissue and bronchoalveolar lavage fluid, respectively, were examined by two-dimensional gel electrophoresis followed by identification of proteins by mass spectrometry. Several proteins were markedly increased in inflamed tissue. In particular, several proteins that are known to be associated with hypoxia were elevated, for example, glycolytic enzymes, glucose-regulated protein 78 kD, prolyl-4-hydroxylase, peroxiredoxin 1, and arginase. Out of the identified proteins, Ym2 displayed the clearest increase, present at high levels in animals with lung eosinophilia, while being undetectable in control subjects. Furthermore, the levels of cathepsin S were markedly increased in inflamed tissue. Taken together, this study identifies a number of marker proteins associated with the pathogenesis of allergic lung inflammation and indicates a link between allergic airway inflammation and induction of hypoxia-related gene products.     

香烟烟雾暴露诱导气道炎症相关机制和治疗潜力的研究进展

主动吸烟和被动吸烟引起呼吸道损伤,诱发多种疾病,包括气流受限为特征的慢性气道炎症疾病 COPD 和哮喘。香烟烟雾暴露引起气道炎症细胞浸润和炎症介质释放,气道高反应性,加重过敏性气道炎症。近年来国内外学者研究了小鼠暴露于香烟烟雾后 BALF 和肺组织中炎症细胞聚集和炎症介质释放和表达,使已致敏小鼠气道炎症加重,并探索了对于香烟烟雾诱导气道炎症的治疗新靶点。单核基因多态性与成人肺功能相关联,研究发现了香烟烟雾暴露与肺功能的相互作用。核转录因子κB激活酶2抑制剂/核转录因子κB 信号传导通路在香烟烟雾暴露诱导的炎症反应中并不重要,并且可能与COPD 发病无关。     

Characteristics of lower airway inflammatory changes in the minimal persistent inflammation of allergic rhinitis in mice

Objective: This study aims to establish an experimental mouse model of minimal persistent inflammation (MPI), observe the features of inflammation and hyper-responsiveness of the upper/lower airways, and explore the relationship between inflammation and hyper-responsiveness in the upper/lower airways. Methods: Sixty-four female BALB/c mice were randomly divided into four groups: allergic rhinitis (AR) group as positive control, MPI group, negative control group and blank control group. Mice were given high and low-concentrated ovalbumin solution after basic and intensive sensitization to establish AR model and MPI model. Nasal mucosa and lung tissues were stained to observe eosinophil infiltration, goblet cell hyperplasia, and expression of intercellular adhesion molecule 1 (ICAM-1). Airway hyper-responsiveness was assessed. Levels of specific immunoglobulin E (sIgE), interleukin (IL)-4 and IL-5 in peripheral blood, nasal lavage fluid (NLF), and bronchoalveolar lavage fluid (BALF) were detected by Enzyme-linked immunosorbent assay. Results: The eosinophil infiltration and expression of ICAM-1 on nasal mucosa and in lung tissues in the AR and MPI groups were significantly elevated compared to control groups. Goblet cells count increased only in the nasal mucosa and not in lung tissues. Eosinophil and neutrophil count of NLF and BALF in the AR and MPI groups increased significantly compared to control groups. Level of IL-4 did not increase significantly, but sIgE and IL-5 did. Conclusions: Mice in the MPI status exhibits lower airway inflammation and hyper-responsiveness with increase in eosinophil count, goblet cells, ICAM-1, IL-4, and IL-5. These results provide further evidence for the importance of MPI of AR in lower airway diseases.