Asthma, Occupational ; etiology ; pathology ; Humans ; Inflammation ; pathology ; Neutrophil Infiltration ; Neutrophils ; pathology

Allergens ; immunology ; Animals ; Asthma ; etiology ; Enzyme Activation ; Lung ; pathology ; Matrix Metalloproteinases ; physiology ; Mice ; Respiratory Syncytial Virus Infections ; enzymology ; pathology

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

OBJECTIVETo investigate the roles of FIZZ1 and NOTCH1 in the pathogenesis of asthma and the effect of rosiglitazone on airway remodeling.

METHODSForty-five healthy 6 to 8-week-old Sprague-Dawley rats were randomly divided into a control group and asthma groups with and without rosiglitazone treatment. The paraffin slices of lung tissues were made to assess the histological changes. a-SMA protein, a specific marker of airway remodeling, in lung tissues was measured by immunohistochemistry. FIZZl-mRNA and NOTCH1-mRNA expression in lung tissues was measured by RT-PCR.

RESULTSThe characteristic changes of airway remodeling were observed in the untreated asthma group. The histological changes in the airway were less severe in the rosiglitazone treated asthma group. Positive a-SMA staining, FIZZl-mRNA and NOTCH1-mRNA were highly expressed in peribronchial lung sections isolated from the untreated asthma group. Rosiglitazone treatment decreased significantly the expression of a-SMA protein, FIZZl-mRNA and NOTCH1-mRNA compared with the untreated asthma group, but the expression of a-SMA protein, FIZZl-mRNA and NOTCH1-mRNA in the rosiglitazone treated asthma group remained higher than the control group. a-SMA expression was positively correlated with FIZZl-mRNA (r=0.826, P<0.01) and NOTCH1-mRNA expression (r=0.9, P<0.01). FIZZl-mRNA expression was positively correlated with NOTCH1-mRNA expression (r=0.76, P<0.01).

CONCLUSIONSFIZZl and NOTCH1 may induce an increase in a-SMA expression. FIZZl and NOTCH1 play a critical role in the process of airway remodeling. Rosiglitazone treatment may inhibit airway remodeling in asthmatic rats.

Actins ; Airway Remodeling ; Animals ; Asthma ; etiology ; pathology ; Lung ; metabolism ; pathology ; Male ; Nerve Growth Factor ; genetics ; physiology ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Receptor, Notch1 ; genetics ; physiology

BACKGROUNDIt has already been recognized that psychosocial stress evokes asthma exacerbation; however, the mechanism of how stress gets inside the body is not clear. This study aimed to observe the impact of psychosocial stress on airway inflammation and its mechanism in the ovalbumin-induced asthmatic mice combined with social disruption stress.

METHODSThirty-six male BALB/c mice were randomly divided into: control group, asthma group (ovalbumin-induced), asthma plus social disruption stress group (SDR), and SDR group. The open field video tracking system was used to assess animal behaviors. The invasive pulmonary resistance (RL) and dynamic lung compliance (cdyn) test system from Buxco was applied to detect pulmonary function. The enzyme-linked immunosorbent assay (ELISA) was utilized to determine OVA-IgE, T-helper type 2 (Th2) cytokines (IL-4, IL-5, IL-13) and corticosterone in mouse serum, the Th2 cytokines (IL-4, IL-5, IL-13, IL-6, TNF-α) in bronchoalveolar lavage fluid (BALF), and IL-6 and TNF-α levels in the supernatant of splenocytes cultured in vitro. Hematoxylin-eosin (H&E) staining was used to assess airway inflammation in lung histology. The cell count kit-8 assay (CCK-8) was applied to evaluate the inhibitory effect of corticosterone on splenocyte proliferation induced by lipopolysaccharide (LPS). Real time-PCR and Western blotting were utilized to determine glucocorticoid receptor (GR) mRNA and GR protein expression in lungs.

RESULTSThe open field test showed that combined allergen exposure and repeated stress significantly shortened the time the mice spent in the center of the open field (P < 0.01), increased ambulatory activity (P < 0.01) and the count of fecal boli (P < 0.01), but deceased vertical activity (P < 0.01). Results from pulmonary function demonstrated that airway hyperresponsiveness (AHR) was enhanced by psychosocial stress compared with allergy exposure alone. The ELISA results showed that cytokines in serum and BALF were significantly increased (P < 0.05). Moreover, the lung histology showed that infiltrated inflammatory cells were significantly increased in the asthma-SDR group compared with the asthma group (P < 0.05). Interestingly, serum corticosterone was remarkably raised by psychosocial stress (P < 0.05). In addition, the inhibitory effect of corticosterone on IL-6 and TNF-α in LPS-stimulated splenocyte cultures in vitro was diminished in the asthma-SDR group compared to the asthma group. The CCK-8 test revealed that the inhibition effect of corticosterone on splenocyte proliferation induced by LPS was significantly impaired in the SDR and asthma-SDR groups, while no significant effect was observed in the control and asthma groups. Furthermore, expression of GR mRNA and GR protein were significantly reduced in the lung tissues of the asthma-SDR group (P < 0.05).

CONCLUSIONSSocial disruption stress can promote anxiety behavior, activate the hypothalamic-pituitary-adrenal (HPA) axis, increase AHR and inflammation, and also impair glucocorticoid sensitivity and its function in a murine model of asthma. The down-regulation of GR expression induced by social disruption stress is in part associated with glucocorticoid insensitivity, which leads to asthma exacerbation.

Animals ; Anxiety ; etiology ; Asthma ; etiology ; Bronchial Hyperreactivity ; etiology ; Corticosterone ; blood ; Cytokines ; biosynthesis ; Disease Models, Animal ; Lung ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; Receptors, Glucocorticoid ; analysis ; physiology ; Stress, Psychological ; complications

Although animal models with ovalbumin have been used to study chronic asthma, there are difficulties in inducing recurrence as well as in maintaining chronic inflammation in this system. Using a murine model of house dust mite (HDM)-induced bronchial asthma, we examined the airway remodeling process in response to the chronic exposure to HDM. During the seventh and twelfth weeks of study, HDM were inhaled through the nose for three consecutive days and airway responsiveness was measured. Twenty-four hours later, bronchoalveolar lavage and histological examination were performed. The degree of overproduction of mucus, subepithelial fibrosis, and the thickness of the peribronchial smooth muscle in the experimental group was clearly increased compared to the control group. In addition, HDM-exposed mice demonstrated severe airway hyperreactivity to methacholine. In the bronchoalveolar lavage fluid, the number of total cells and eosinophils was increased; during the twelfth week, the number of neutrophils increased in the experimental group. With regard to changes in cytokines, the concentrations of IL-4, IL- 13, and transforming growth factor-beta (TGF-beta) were increased in the experimental group. The data suggest that eosinophils, IL-4, IL-13, and TGF-beta might play an important role in the airway remodeling process and that neutrophils may be involved with increased exposure time.
Animals ; Asthma/*etiology/pathology ; Eosinophils/physiology ; Female ; Immunoglobulin E/blood ; Immunoglobulin G/blood ; Inflammation/*etiology ; Interleukin-13/physiology ; Interleukin-4/physiology ; Lung/*pathology ; Mice ; Mice, Inbred BALB C ; Pyroglyphidae/*immunology ; Transforming Growth Factor beta/physiology

OBJECTIVETo study the effects of the change in transient receptor potential vanilloid 1 (TRPV1) channel activity on the degree of airway inflammation in asthmatic mice.

METHODSBALB/c mice were randomly divided into control, asthma, capsaicin (TRPV1 agonist), capsazepine (TRPV1 antagonist), and dexamethasone groups. The asthmatic mouse model was established by intraperitoneal injection of mixed ovalbumin-aluminium hydroxide solution and ultrasonic atomization with OVA for sensitization and challenge. The capsaicin, capsazepine, and dexamethasone groups were given intraperitoneal injection of capsaicin (30 μg/kg), capsazepine (10 μmol/kg), and dexamethasone (2 mg/kg) respectively, at 30 minutes before challenge. Hematoxylin and eosin staining was used to observe the degree of pulmonary inflammation. ELISA was used to measure the content of interleukin-8 (IL-8) and interleukin-13 (IL-13) in bronchoalveolar lavage fluid (BALF). Real-Time PCR was used to measure the relative content of TRPV1 mRNA in lung tissue.

RESULTSCompared with the asthma group, the capsazepine and dexamethasone groups showed reduced pulmonary inflammation, while the capsaicin group showed aggravated pulmonary inflammation. Compared with the control group, the asthma and capsaicin groups showed increases in the content of IL-13 and IL-8 in BALF and the mRNA expression of TRPV1 in lung tissue (P<0.05). Compared with the asthma group, the capsazepine and dexamethasone groups showed reductions in the content of IL-13 and IL-8 in BALF and the mRNA expression of TRPV1 in lung tissue (P<0.05). The capsaicin group showed increases in the content of IL-13 and IL-8 in BALF (P<0.05).

CONCLUSIONSTRPV1 channel agonist and antagonist can influence the degree of airway inflammation in asthmatic mice. Dexamethasone may reduce airway inflammation through regulating TRPV1 level.

Animals ; Asthma ; etiology ; Female ; Interleukin-13 ; analysis ; Interleukin-8 ; analysis ; Lung ; pathology ; Mice ; Mice, Inbred BALB C ; RNA, Messenger ; analysis ; TRPV Cation Channels ; genetics ; physiology

OBJECTIVETo investigate the changes in the mRNA and protein expression of high-mobility group box 1 (HMGB1), Toll-like receptor 4 (TLR4), and nuclear factor-kappa B (NF-κB) in lung tissues of asthmatic mice and the interventional effect of vitamin D.

METHODSA total of 48 BALB/c mice were randomly divided into control group, asthma group, and 1,25-(OH)Dintervention group, with 16 mice in each group. An animal model of asthma was established, and lung tissue samples were taken in each group at weeks 1 and 2 of ovalbumin challenging. Conventional hematoxylin-eosin staining was used to measure airway wall thickness. Immunohistochemical staining was used to observe the expression of HMGB1, TLR4, and NF-κB in lung tissues. Quantitative real-time PCR and Western blot were used to investigate the changes in the mRNA and protein expression of HMGB1, TLR4, and NF-κB.

RESULTSAt weeks 1 and 2 of ovalbumin challenging, compared with the control group, the asthma group had a significant increase in airway wall thickness and the intervention group had a significant reduction compared with the asthma group (P<0.05). The asthma group had significantly higher mRNA expression of HMGB1, TLR4, and NF-κB in lung tissues than the control group, and the intervention group had significantly lower mRNA expression of TLR4 and NF-κB than the asthma group (P<0.05). At week 1 of ovalbumin challenging, there was no significant difference in the mRNA expression of HMGB1 between the intervention group and the asthma group (P>0.05). At week 2, the intervention group had a significant reduction in the mRNA expression of HMGB1 compared with the asthma group (P<0.05). At weeks 1 and 2 of ovalbumin challenging, the asthma group had significantly higher protein expression of HMGB1, TLR4, and NF-κB in lung tissues than the control group, and the intervention group had significantly lower expression than the asthma group (P<0.05). Airway wall thickness was positively correlated with the mRNA expression of HMGB1, TLR4, and NF-κB in lung tissues (r=0.804, 0.895, and 0.834; P<0.05).

CONCLUSIONSThe HMGB1/TLR4/NF-κB signaling pathway plays an important role in the pathogenesis of asthma, and an appropriate amount of 1,25-(OH)Dhas a regulatory effect on this pathway and may prevent the progression of asthma. Therefore, 1,25-(OH)Dis expected to become a new choice for the treatment of asthma.

Animals ; Asthma ; drug therapy ; etiology ; pathology ; Calcitriol ; therapeutic use ; Female ; HMGB1 Protein ; analysis ; physiology ; Lung ; pathology ; Mice ; Mice, Inbred BALB C ; NF-kappa B ; analysis ; physiology ; Signal Transduction ; physiology ; Toll-Like Receptor 4 ; analysis ; physiology

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

OBJECTIVETo investigate the pathogenic mechanisms of airway inflammation and recurrent wheezing induced by recurrent respiratory virus infection after respiratory syncytial virus (RSV) infection.

METHODSSixty-four female BALB/c mice (aged 6-8 weeks) were randomly divided into four groups: control, RSV, Poly(I:C), and RSV+Poly(I:C) (n=16 each). The bronchoalveolar lavage fluid (BALF) was collected on the 3rd day after Poly(I:C) administration, and the total cell number and differential counts in BALF were determined. Hematoxylin-eosin staining was used to observe pulmonary pathological changes. The airway responsiveness was detected. ELISA was used to measure the levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), interleukin-13 (IL-13), matrix metallopeptidase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in BALF.

RESULTSCompared with the other three groups, the RSV+Poly(I:C) group had significant increases in the total number of inflammatory infiltrating cells in the airway, airway responsiveness, and MMP-9 level in BALF (P<0.05). The RSV+Poly(I:C) group showed more severe pulmonary tissue injuries compared with the control and RSV groups (P<0.01). Compared with the RSV group, the RSV+Poly(I:C) group showed significant reductions in the levels of IL-4 and TIMP-1 in BALF (P<0.01).

CONCLUSIONSViral re-infection in the late stage of RSV infection may cause an imbalance of MMP-9/TIMP-1 expression and thus contribute to aggravated airway inflammation.

Animals ; Asthma ; etiology ; Bronchoalveolar Lavage Fluid ; chemistry ; Female ; Lung ; pathology ; Matrix Metalloproteinase 9 ; analysis ; Mice ; Mice, Inbred BALB C ; Poly I-C ; pharmacology ; Respiratory Syncytial Virus Infections ; complications ; Tissue Inhibitor of Metalloproteinase-1 ; analysis