Airway remodeling in asthma is a result of persistent inflammation and epithelial damage in response to repetitive injury. Recent studies have identified several important mediators associated with airway remodeling in asthma, including transforming growth factor-beta, interleukin (IL)-5, basic fibroblast growth factor, vascular endothelial growth factor, LIGHT, tumor necrosis factor (TNF)-alpha, thymic stromal lymphopoietin, IL-33, and IL-25. In addition, the epithelium mesenchymal transformation (EMT) induced by environmental factors may play an important role in initiating this process. Diagnostic methods using sputum and blood biomarkers as well as radiological interventions have been developed to distinguish between asthma sub-phenotypes. Human clinical trials have been conducted to evaluate biological therapies that target individual inflammatory cells or mediators including anti IgE, anti IL-5, and anti TNF-alpha. Furthermore, new drugs such as c-kit/platelet-derived growth factor receptor kinase inhibitors, endothelin-1 receptor antagonists, calcium channel inhibitors, and HMG-CoA reductase inhibitors have been developed to treat asthma-related symptoms. In addition to targeting specific inflammatory cells or mediators, preventing the initiation of EMT may be important for targeted treatment. Interestingly, bronchial thermoplasty reduces smooth muscle mass in patients with severe asthma and improves asthma-specific quality of life, particularly by reducing severe exacerbation and healthcare use. A wide range of different therapeutic approaches has been developed to address the immunological processes of asthma and to treat this complex chronic illness. An important future direction may be to investigate the role of mediators involved in the development of airway remodeling to enhance asthma therapy.
Airway Resistance/*immunology ; Asthma/immunology/*pathology/therapy ; Biological Therapy ; Cytokines ; Eosinophils ; Epithelium ; Humans ; Inflammation/immunology/*pathology/therapy ; Interleukin-5 ; Tumor Necrosis Factor-alpha

OBJECTIVETo investigate bronchial responsiveness to acetylcholine in allergic airway inflammation of SD rats.

METHODSSD rats were immunized and challenged by chicken ovalbumin (OVA). Airway responsiveness, acetylcholine (Ach) provocation concentration needed to increase baseline airway resistance by 200% (PC(200)) were measured.

RESULTSThe value of baseline airway resistance in asthma group was significantly higher than that in control group (2.282 +/- 0.128 vs 3.193 +/- 0.239; P < 0.01). After multiple ovalbumin exposures, airway responsiveness to intravenous injection of acetylcholine decreased significantly (-LogPC(200): 4.006 +/- 0.554 vs 2.059 +/- 0.262; P < 0.01). Bronchial alveolar lavage fluid (BALF) and lung tissue specimen analysis indicated that airway allergic inflammation was present.

CONCLUSIONSThe study demonstrates a dissociation between the bronchoconstrictor response and bronchial hyper-responsiveness and indicates that multiple ovalbumin exposures induces persistent bronchoconstriction with airway hypo-responsiveness despite airway allergic inflammation.

Acetylcholine ; pharmacology ; Airway Resistance ; Allergens ; immunology ; Animals ; Bronchi ; drug effects ; physiology ; Bronchial Hyperreactivity ; etiology ; Bronchoconstriction ; Lung ; pathology ; Male ; Ovalbumin ; immunology ; Rats ; Rats, Sprague-Dawley

BACKGROUNDAirway hyperresponsiveness (AHR) is one of the most important characteristics of asthma. This study investigated the parameters, by which assess the airway responsiveness under tidal ventilation.

METHODSFemale BALB/c mice were sensitized and challenged with ovalbumin (OVA) (group A), and part of them were treated with budesonide aerosol (group B). All the mice were anaesthetized and mechanically ventilated. The values of tidal volume (Vt), airway pressure (PA), airway flow (F), expiratory lung resistance (RL) and dynamic compliance of the thorax and lung (CT-L) were recorded by the AniRes2003 animal lung function system. In addition, the expiratory volume in the first 0.1 second after the start of expiration (EV0.1) was obtained according to the flow-volume (F-V) curve. The maximal or minimal values of EV0.1, RL and CT-L were documented after each dose of methacholine (MCH) and compared with values from negative control group (group C).

RESULTS(1) When the dose of MCH reached 100 ng/g or 200 ng/g, the decrease of Vt in group A was much more significant than group C (P = 0.001, < 0.001 respectively), but not so between groups B and group C (P = 0.974, 0.362 respectively). (2) With the dose of 25, 50, 100 or 200 ng/g MCH, the decrease in percentage of EV0.1 in group A was much higher than group C (P = 0.012, 0.025, 0.001, 0.003 respectively), while that in group B showed no significant difference as compared with group C (P = 0.507, 0.896, 0.972, 0.785). (3) RL and CT-L: with the dose of 200 ng/g MCH, there was a statistically significant increase of RL in group A compared to group B or group C (P < 0.001, < 0.001 respectively), but no significant difference between groups B and C (P = 0.266). With doses of 100 ng/g and 200 ng/g MCH, there was a statistically significant decrease of CT-L in group A compared to group B (P = 0.001, = 0.001) and group C (P < 0.001, < 0.001 respectively), but no significant difference between groups B and C (P = 0.775, 0.310). (4) Histopathology: there were eosinophilic predominant peribronchial and perivascular inflammatory influx in murine lungs after OVA sensitizing and challenging, which could be counteracted by inhalation of budesonide in group B.

CONCLUSIONSThe decline in EV0.1 in response to MCH challenge correlated with simultaneous changes in Vt, RL and CT-L, but more sensitively than all the other parameters. The decline in EV0.1 and inflammation in murine lung could be significantly alleviated by inhalation of nebulized budesonide solution, which indicated that EV0.1 to MCH is a valid measure of AHR in mice.

Airway Resistance ; drug effects ; Animals ; Bronchial Hyperreactivity ; drug therapy ; Budesonide ; therapeutic use ; Female ; Lung Compliance ; drug effects ; Methacholine Chloride ; pharmacology ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; immunology

OBJECTIVETo prepare a mouse model of asthma by sensitizing and challenging with house dust mite allergen Derp and evaluate its reliability by measuring airway allergy inflammation and airway responsiveness.

METHODSTwelve C57BL/6J mice were randomly divided into two groups: control and asthma model. Mice of the asthma model group were sensitized by intraperitoneal injection of house dust mite allergen Derp on the first and tenth days of the experiment. From the 17th day, the mice were challenged by intranasal Derp, once every other day, seven times. The control group was treated with normal sodium instead of Derp. Twenty-four hours after the last challenge, airway responsiveness was evaluated. Bronchoalveolar lavage and histological examination of the lung were performed.

RESULTSAirway resistance increased and dynamic lung compliance decreased significantly in the asthma model group as compared to the control group (P<0.01). When airway resistance increased by 25% and dynamic lung compliance decreased by 15%, the required metacholine concentration in the asthma model group was significantly lower than that in the control group (P<0.01). In the bronchoalveolar lavage fluid of the asthma model group, the number of total cells, absolute number of eosinophils (EOS) and the percentage of EOS in the total cell were significantly higher than those in the control group (P<0.01). Pulmonary pathological scores in the asthma model group were significantly higher than those in the control group (P<0.01). The asthma model group showed ultrastructural changes of bronchial and pulmonary arterioles. Goblet cells, mastocyte granules, and increased mucus were observed in the lung tissues of the asthma model group.

CONCLUSIONSA mouse model of asthma was prepared by sensitizing and challenging with house dust mite allergen Derp, with the characteristics of airway allergy inflammation and airway hypersensitivity reaction.

Airway Resistance ; Animals ; Arterioles ; ultrastructure ; Asthma ; etiology ; pathology ; physiopathology ; Disease Models, Animal ; Eosinophils ; pathology ; Female ; Lung ; pathology ; ultrastructure ; Lung Compliance ; Mice ; Mice, Inbred C57BL ; Pyroglyphidae ; immunology

AIM: Ma Huang Tang (Ephedra decoction, MHT) is a famous classical formula from Shang Han Lun by Zhang Zhongjing in the Han Dynasty. The anti-asthmatic effects of MHT and the possible mechanisms were tested. METHOD: An asthma model was established by ovalbumin (OVA)-induction in mice. A total of forty-eight mice were randomly assigned to six experimental groups: control, model, dexamethasone (2 mg·kg(-1)) and MHT (5, 10, and 20 mg·kg(-1)). Airway resistance (Raw) was measured by the forced oscillation technique, histological studies were evaluated by hematoxylin and eosin (HE) staining, Th1/Th2 and Th17 cytokines were evaluated by enzyme-linked immunosorbent assay (ELISA), and Th17 cells were evaluated by flow cytometry (FCM). RESULTS: This study demonstrated that MHT inhibited OVA-induced increases in Raw and eosinophil count; interleukin (IL)-4 and IL-17 levels were recovered in bronchoalveolar lavage fluid, increased IFN-γ level in bronchoalveolar lavage fluid. Histological studies demonstrated that MHT substantially inhibited OVA-induced eosinophilia in lung tissue. Flow cytometry studies demonstrated that MHT substantially inhibited Th17 cells. CONCLUSION These findings suggest that MHT may effectively ameliorate the progression of asthma, and could be further investigated for potential use as a therapy for patients with allergic asthma.
Airway Resistance ; drug effects ; Animals ; Anti-Asthmatic Agents ; administration & dosage ; Asthma ; chemically induced ; drug therapy ; immunology ; physiopathology ; Cytokines ; immunology ; Down-Regulation ; drug effects ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Humans ; Mice ; Mice, Inbred BALB C ; Ovalbumin ; adverse effects ; Th1 Cells ; drug effects ; immunology ; Th17 Cells ; drug effects ; immunology ; Th2 Cells ; drug effects ; immunology

OBJECTIVEThe role of air pollution on asthma can not be ignored, diesel exhaust particles (DEP) in the air is one of the most important pollutants. This study aimed to investigate the effect and mechanism of DEP inhaled on immediate reaction in the asthma rats.

METHODSixty male Wistar rats of "Clean" grade, 6 - 7 week-old, with an average weight of (140 +/- 20) g were used in this study. The rats were randomly divided into 6 groups, 10 in each. Group A was treated with normal saline attack as a negative control, Group B with ovalbumin attack as a positive control. After ovalbumin attack, groups C, D, E, F continued to inhale DEP for 1 week, 2 weeks, 3 weeks and 4 weeks, respectively. The concentration of DEP was 200 microg/ml, the animals were subjected to inhalation of ultrasound nebulized DEP for 30 min per day. One week after all the attacks were concluded, Group A was stimulated with normal saline for 30 min, other groups were stimulated with ovalbumin. Then the airway resistance was determined with multi-channel signal acquisition and processing system and compared. The changes in neutrophils, eosinophils, and other inflammatory cells of BALF and the pathological changes in lung tissue, including epithelial cells loss, the inflammatory cells infiltration around the airway, basement membrane fibrosis, goblet cell hyperplasia etc. were observed. The concentration of IL-5 and gamma-interferon in the lung tissues, and the changes of serum IgE etc. were determined.

RESULTAirway resistance values of group A, B, C, D, E, F after ovalbumin excitation for 30 min were (3.56 +/- 0.21), (7.06 +/- 0.63), (6.46 +/- 0.38), (7.47 +/- 0.33), (8.87 +/- 0.61), (11.00 +/- 0.69) cm H2O/(ml.s). No airway hyperresponsiveness occurred in group A, while Groups B, C, D, E, F had higher airway resistance than group A, group E and F had higher airway resistance than that of group B, the differences were statistically significant. And the airway resistance was different in each group among 0 min, 10 min, 20 min and 30 min (F = 160.646, 148.901, 162.204, 156.186, P < 0.01 for both). The time of DEP inhalation and the airway resistance was positively correlated (r = 0.948, P < 0.01); IgE concentrations of the serum between groups B, C, D, E, F was not significantly different (P > 0.05), but higher than that of group A (F = 2.639, P < 0.01). The infiltrated inflammatory cells included eosinophils and lymphocytes, etc. The percentages of neutrophil(%) were (4.3 +/- 2.0), (9.7 +/- 5.2), (10.3 +/- 5.6), (13.0 +/- 5.2), (42.6 +/- 18.3), (55.3 +/- 6.9). The groups E and F had higher percentage than Group A and Group B (F = 114.226, P < 0.01). The percentages of eosinophils(%) were 0, (11.9 +/- 3.8), (15.8 +/- 6.3), (13.0 +/- 4.9), (21.1 +/- 5.6), (27.1 +/- 4.8). The difference between Groups B, C, D, E, F and Group A was statistically significant. There was significant difference between groups C, D, E, F and group B (F = 46.462, P < 0.05); Lung tissue biopsy in group A showed that the epithelial cells were intact, no inflammatory cells infiltrations were found around the airways, instead, mainly ciliated columnar epithelial cells and only a small number of goblet cells were seen without basement membrane fibrosis. With the inhalation of DEP, the epithelial cells showed gradual necrosis, disruption and loss, goblet cells showed hyperplasia, and infiltrations with inflammatory cells were seen around the airway. In the lung tissue, concentrations of IL-5 in group B, C, and E were (12.8 +/- 2.8), (17.1 +/- 5.2), (18.6 +/- 4.2) pg/mg, the difference between groups C, E and group B was statistically significant (F = 4.236, P < 0.01), the difference in gamma-interferon concentration among all groups was not statistically significance (F = 1.185, P > 0.05).

CONCLUSIONDEP inhalation increased the airway responsiveness of asthma rats in immediate reaction, promoted the lung epithelial cell loss, inflammatory cell infiltration, basement membrane fibrosis and goblet cell hyperplasia.

Air Pollutants ; adverse effects ; Airway Resistance ; Animals ; Asthma ; immunology ; metabolism ; pathology ; Disease Models, Animal ; Hypersensitivity, Immediate ; etiology ; Immunoglobulin E ; blood ; Interferon-gamma ; metabolism ; Interleukin-5 ; metabolism ; Lung ; metabolism ; pathology ; Male ; Rats ; Rats, Wistar ; Vehicle Emissions

Gap junction channels formed with connexins directly link to the cytoplasm of adjacent cells and have been implicated in intercellular signaling. Connexin 37 (Cx37) is expressed in the gas-exchange region of the lung. Recently, Cx37 has been reported to be involved in the pathogenesis of inflammatory disease. However, no data are available on the role of Cx37 in allergic airway inflammatory disease. In the present study, we used a murine model of ovalbumin (OVA)-induced allergic airway disease and primary murine epithelial cells to examine the change of Cx37 in allergic airway disease. These mice develop the following typical pathophysiological features of asthma: airway hyperresponsiveness, airway inflammation, and increased IL-4, IL-5, IL-13, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, eotaxin, and RANTES levels in lungs. Cx37 protein and mRNA expression were decreased in OVA-induced allergic airway disease. Immunoreactive Cx37 localized in epithelial layers around the bronchioles in control mice, which dramatically disappeared in allergen-induced asthmatic lungs. Moreover, the levels of Cx37 protein in lung tissues showed significantly negative correlations with airway inflammation, airway responsiveness, and levels of Th2 cytokines in lungs. These findings indicate that change of Cx37 may be associated with the asthma phenotype.
Airway Resistance ; Allergens/toxicity ; Animals ; Asthma/etiology/genetics/immunology/*metabolism ; Base Sequence ; Bronchoalveolar Lavage Fluid/cytology ; Cell Adhesion Molecules/metabolism ; Cells, Cultured ; Chemokines/metabolism ; Connexins/genetics/*metabolism ; Cytokines/metabolism ; DNA Primers/genetics ; Disease Models, Animal ; Epithelial Cells/metabolism ; Female ; Lung/immunology/metabolism/pathology ; Mice ; Mice, Inbred C57BL ; Ovalbumin/immunology/toxicity ; RNA, Messenger/genetics/metabolism ; Trachea/metabolism

AIMTo establish an antigen-specific asthmatic model of guinea pig induced by protein antigen extracted from Dermatophagoides farinae (Der f), and study the desensitization of dust mite drops (DMD, extracted from Der f) in a dose progressive manner and long-term sublingual administration.

METHODSTo sensitize the guinea pigs, the protein antigen emulsified in aluminium hydroxide gel was subcutaneously and intraperitoneally injected. To observe early-phase reaction of asthma, lung resistance (R(L)) and lung dynamic compliance (Cdyn) in the sensitized guinea pigs were determined by intravenously injecting antigen. To observe late-phase reaction of asthma, the sensitized guinea pigs were challenged with aerosolized antigen for 7 days. Subsequently, methacholine (Mch) in a cumulative dose-manner induced-airway hyperreactivity (AHR), inflammatory cells numbers in bronchoalveolar lavage fluid (BALF) and pathological changes of lung tissue were measured in the model. From the first day of sensitization, the guinea pigs in treatment group sublingually received DMD in a dose progressive manner. The model group sublingually received equivalent saline. The normal control group did not receive any treatment.

RESULTSThe guinea pigs in model group showed a significant increase in R(L) and decrease in Cdyn, and developed a marked AHR to Mch. The number of total leukocytes and eosinophils increased significantly in BALF. Serious infiltration of eosinophils was observed in pathological section of lung tissue. Compared with model group, DMD treatment group exhibited a significant amelioration for early-phase and late-phase reaction of asthma.

CONCLUSIONDMD in a dose progressive manner and long-term sublingual administration displays a significant desensitization on Der f antigen-specific asthmatic reaction. The results provided experimental evidence for clinical therapy.

Administration, Sublingual ; Airway Resistance ; drug effects ; Allergens ; immunology ; Animals ; Antigens, Dermatophagoides ; administration & dosage ; isolation & purification ; therapeutic use ; Asthma ; immunology ; physiopathology ; therapy ; Bronchoalveolar Lavage Fluid ; cytology ; Dermatophagoides farinae ; immunology ; Desensitization, Immunologic ; methods ; Eosinophils ; drug effects ; pathology ; Female ; Guinea Pigs ; Leukocyte Count ; Lung Compliance ; drug effects ; Male