The role of alveolar macrophages (AMs) in the pathogenesis of asthma is still unknown. The aim of the present study was to investigate the effects of AM in the murine model of asthma. AMs were selectively depleted by liposomes containing clodronate just before allergen challenges, and changes in inflammatory cells and cytokine concentrations in bronchoalveolar lavage (BAL) fluid were measured. AMs were then adoptively transferred to AM-depleted sensitized mice and changes were measured. Phenotypic changes in AMs were evaluated after in vitro allergen stimulation. AM-depletion after sensitization significantly increased the number of eosinophils and lymphocytes and the concentrations of IL-4, IL-5 and GM-CSF in BAL fluid. These changes were significantly ameliorated only by adoptive transfer of unsensitized AMs, not by sensitized AMs. In addition, in vitro allergen stimulation of AMs resulted in their gaining the ability to produce inflammatory cytokines, such as IL-1beta, IL-6 and TNF-alpha, and losing the ability to suppress GM-CSF concentrations in BAL fluid. These findings suggested that AMs worked probably through GM-CSF-dependent mechanisms, although further confirmatory experiments are needed. Our results indicate that the role of AMs in the context of airway inflammation should be re-examined.
Animals ; Asthma/*immunology ; Bronchoalveolar Lavage Fluid/chemistry/cytology/immunology ; Cytokines/biosynthesis/immunology ; Disease Models, Animal ; Female ; Immunization ; Immunomodulation/*immunology ; Inflammation/*immunology ; Leukocytes/immunology ; Macrophages, Alveolar/*immunology ; Mice ; Mice, Inbred C57BL ; Ovalbumin/immunology

OBJECTIVETo investigate the changes in the levels of interleukin-17 (IL-17) and transforming growth factor beta 1 (TGF-β1) in serum and bronchoalveolar lavage fluid (BALF) and their clinical significance among children with asthma.

METHODSFifty-six children with asthma were divided into moderate or severe asthma (n=37) and mild asthma groups (n=19) and 18 children without asthma were selected as the control group. Cells in BALF were counted under a microscope. The levels of IL-17 and TGF-β1 in serum and BALF were measured using ELISA.

RESULTSwere no significant differences in total cell count and percentage of macrophages between the two asthma groups and the control group (P>0.05). The percentages of neutrophils, eosinophils and epithelial cells in BALF were significantly higher in the two asthma groups than in the control group (P<0.05). The two asthma groups had significantly higher levels of IL-17 and TGF-β1 in serum and BALF than the control group (P<0.05), and the moderate or severe asthma group had significantly higher levels of IL-17 and TGF-β1 in serum and BALF than the mild asthma group (P<0.05). Levels of IL-17 and TGF-β1 in serum were significantly positively correlated with those in BALF (r=0.935 and 0.943, P<0.05 for both). In children with asthma, serum IL-17 level was significantly positively correlated with the percentage of neutrophils, eosinophils and epithelial cells in BALF (r=0.802, 0.799, and 0.674, P<0.05 for all), and a significant positive correlation was also seen between serum levels of IL-17 and TGF-β1 (r=0.878, P<0.05).

CONCLUSIONSLevels of IL-17 and TGF-β1 in serum and BALF are elevated in children with asthma. IL-17 and TGF-β1 may be involved in the occurrence and development of asthma, and they play important roles in asthma attack and aggravation.

Asthma ; immunology ; pathology ; Bronchoalveolar Lavage Fluid ; chemistry ; cytology ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Interleukin-17 ; analysis ; blood ; physiology ; Male ; Transforming Growth Factor beta1 ; analysis ; blood ; physiology

OBJECTIVES: We established a Wistar rat model of asthma caused by toluene diisocyanate (TDI) exposure, and investigated the relationship between TDI exposure concentrations and respiratory hypersensitivity, airway inflammation, and cytokine secretions in animals, to better understand the mechanism of TDI induced occupational asthma. METHODS: Wistar rats were exposed to two different concentrations of TDI vapor four hours a day for five consecutive days. Bronchoalveolar lavage (BAL) was performed, and differential leucocytes from the BAL fluid were analyzed. Lung histopathological examination was carried out to investigate the inflammatory status in the airways. Production of cytokines interleukin (IL)-4 and IL-5 productions in the BAL fluid in vivo was determined with enzyme-linked immunosorbent assay kits. RESULTS: The TDI-exposed rats exhibited greater airway hypersensitivity symptoms than the control rats. The BAL differential cell count and lung histopathological examination demonstrated that inflammation reactions were present in both the central and peripheral airways, characterized with marked infiltration of eosinophils in the TDI-exposed rats. The cytokine assay showed that IL-4 and IL-5 were predominantly produced in the BAL fluid in vivo. CONCLUSIONS: These findings imply that TDI exposure concentrations may greatly affect the occurrence and extent of inflammatory events and that Th2 type cytokines may play an important role in the immunopathogenesis of TDI-induced occupational respiratory hypersensitivity.
Animals ; Bronchoalveolar Lavage Fluid/chemistry/cytology ; Enzyme-Linked Immunosorbent Assay ; Eosinophils/cytology/immunology ; Female ; Gases/chemistry ; Hypersensitivity/pathology ; Interleukin-4/*analysis ; Interleukin-5/*analysis ; Lung/*drug effects/pathology/secretion ; Rats ; Rats, Wistar ; Toluene 2,4-Diisocyanate/*toxicity

OBJECTIVENuclear factor-kappa B (NF-kappaB) is a critical transcription factor governing the expression of many cytokines that are involved in the pathogenesis of inflammatory diseases, such as asthma and rheumatoid arthritis. Melatonin (MT), a relatively safe and potent antioxidant which has shown efficacy in several chronic inflammatory models, may inhibit the expression of NF-kappaB and therefore might have a therapeutic use in asthma. This study aimed at observing the effect of MT on the expression of NF-kappaB and airway inflammation in a rat model of bronchial asthma.

METHODSTwenty-four male Sprague-Dawley (SD) rats weighing 120 g to 170 g were randomly divided into three experimental groups (8 in each): (1) Asthmatic group: Rats were immunized on day 1 by intraperitoneal injection of 100 mg ovalbumin (OVA) in 1 ml of saline with 100 mg of alu minum hydroxide. From day 15 the animals were challenged with aerosolized OVA (1% in saline) for 20 minutes per day for 7 consecutive days. (2) MT group: OVA-sensitized rats were injected intraperitoneally with 10 mg/kg MT 30 minutes before each OVA challenge. (3) CONTROL GROUP: OVA for inhalation and MT for intraperitoneal injection was replaced with normal saline (NS). Airway responsiveness to aerosolized acetylcholine of 24 rats was detected six hours after the last challenge. Then the rats were lavaged and total and differentiated leukocytes counts in bronchoalveolar lavage fluid (BALF) were performed after staining with Wright-Giemsa staining. At the same time, levels of nitric oxide (NO) in BALF, inducible nitric oxide synthesis (iNOS) and constitute nitric oxide synthesis (cNOS) in the lung tissues were assessed with the use of nitrate reductase and chemical colorimetry, respectively. The expression of NF-kappaB in the lung tissues was observed by means of immunohistochemical staining.

RESULTS(1) After OVA challenge, there was a significant decrease in airway responsiveness, lymphocytes and eosinophils in BALF in MT group compared with asthmatic group (P < 0.01 respectively); (2) There was a significant decrease in amounts of NO(2)(-)/NO(3)(-) in the BALF and levels of iNOS in the lung tissues in MT group comparing with asthmatic group (P < 0.01 respectively); and the levels of iNOS in the lung tissues was correlated positively with NO(2)(-)/NO(3)(-) in the BALF (P < 0.01), but there were no significant differences in activity of cNOS in any of the groups analyzed. (3) There was a significant increase in expression of NF-kappaB in lung tissues in asthmatic group compared with the other groups (P < 0.01), and so was in MT group compared with control group (P < 0.05).

CONCLUSIONSMT could partially inhibit the expression of NF-kappaB and down-regulate the activity of iNOS in lung tissue, decrease the production of NO in BALF. These data suggest that the inhibitory effect of MT probably play a role in decreasing airway hyperresponsiveness and airway inflammation of asthmatic rats model.

Animals ; Antioxidants ; pharmacology ; Asthma ; drug therapy ; metabolism ; Bronchoalveolar Lavage Fluid ; cytology ; immunology ; Disease Models, Animal ; Lung ; chemistry ; pathology ; Male ; Melatonin ; pharmacology ; NF-kappa B ; analysis ; Nitric Oxide ; analysis ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the effects of polysaccharides of cultured Cryptoporus volvatus(CVPS) on airway hyperresponsiveness of ovalbumin-sensitized rats and to evaluate their mechanisms.

METHODSPolysaccharides A, B (5mg/kg, 20mg/kg) and ketotifen(5mg/kg) or vehicle(same volume of saline) were administrated orally for 10 days in ovalbumin -sensitized rats, methacholine bronchial provocation tests were performed to determine airway hyperresponsiveness. Bronchoalveolar lavage fluid (BALF) and peritoneal lavage fluid were prepared after the animals were challenged by nebulized antigen. The differential white cell count in BALF,and the degranulated mast cell count as well as differential white cell count in peritoneal lavage fluid were performed.

RESULTPolysaccharides markedly inhibited the increased lung resistance and the decreased lung compliance induced by antigen challenge,significantly reduced total cell counts and absolute eosinophil counts in BALF(P<0.05); polysaccharides B was more effective than polysaccharides A. They also inhibited recruitment of inflammatory cells in peritoneal lavage fluid and inhibited the allergen-induced mast cell degranulation.

CONCLUSIONPolysaccharides of CVPS inhibit airway hyperresponsiveness by stabilizing mast cell membranes and reducing infiltration and chemotaxis of eosinophils and may be developed as a potential anti-asthmatic drug.

Animals ; Anti-Asthmatic Agents ; pharmacology ; Bronchial Hyperreactivity ; drug therapy ; Bronchoalveolar Lavage Fluid ; cytology ; Cell Degranulation ; drug effects ; Male ; Mast Cells ; drug effects ; physiology ; Ovalbumin ; immunology ; Polyporaceae ; chemistry ; Polysaccharides ; pharmacology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo explore the protective effects and mechanism of ethanol extract of Inonotus obliquus (EEIO) injection on asthmatic mice.

METHODOVA was injected intraperitoneally and inhaled to produce the asthmatic model. Thirty two mice were randomly divided into four groups: control group, asthma group and I. obliquus groups of high and low dose. The concentrations of IL-4, IL-5, IL-13 and IFN-gamma in BALF, the phosphor-p38 MAPK in lung tissues were respectively measured by ELISA and Western blotting. The number of inflammatory cells in BALF and histopathology changes were observed.

RESULTIn asthmatic group, the number of inflammatory cells and the concentrations of IL-4, IL-5, IL-13 in BALF and phospho-p38 MAPK in lung tissue were higher, while IFN-gamma were lower than those in normal control mice (P < 0.05). In I. obliquus group, the number of inflammatory cells, the concentrations of IL-4, IL-5, IL-13 in BALF and phosphor-p38 MAPK in lung tissue were lower, but were higher than those in normal control mice (P < 0.05), and histropathology damage was alleviated significantly. There was no significant difference observed among the efficacies in the I. obliquus groups of high and low dose.

CONCLUSIONp38 MAPK may play a role in pathological process of asthma. I. obliquus effectively treats asthma by inhibiting the expression of phosphor-p38 MAPK, correcting the unbalance of IFN-gamma/IL-4 and decreasing the number of inflammatory cells.

Animals ; Anti-Asthmatic Agents ; isolation & purification ; pharmacology ; Asthma ; drug therapy ; metabolism ; pathology ; Basidiomycota ; chemistry ; Basophils ; drug effects ; metabolism ; Bronchoalveolar Lavage Fluid ; cytology ; immunology ; Disease Models, Animal ; Interferon-gamma ; drug effects ; metabolism ; Interleukin-13 ; metabolism ; Interleukin-4 ; metabolism ; Interleukin-5 ; metabolism ; Lung ; pathology ; Lymphocytes ; drug effects ; metabolism ; Mice ; Mice, Inbred BALB C ; Neutrophils ; drug effects ; metabolism ; Phytotherapy ; Plant Extracts ; pharmacology ; p38 Mitogen-Activated Protein Kinases ; drug effects ; metabolism

In the present study, we analyzed the role of Ginkgo biloba extract in lipopolysaccharide(LPS)-induced acute lung injury (ALI). ALI was induced in mice by intratracheal instillation of LPS. G. biloba extract (12 and 24 mg·kg(-1)) and dexamethasone (2 mg·kg(-1)), as a positive control, were given by i.p. injection. The cells in the bronchoalveolar lavage fluid (BALF) were counted. The degree of animal lung edema was evaluated by measuring the wet/dry weight ratio. The superoxidase dismutase (SOD) and myeloperoxidase (MPO) activities were assayed by SOD and MPO kits, respectively. The levels of inflammatory mediators, tumor necrosis factor-a, interleukin-1b, and interleukin-6, were assayed by enzyme-linked immunosorbent assay. Pathological changes of lung tissues were observed by H&E staining. The levels of NF-κB p65 and COX-2 expression were detected by Western blotting. Compared to the LPS group, the treatment with the G. biloba extract at 12 and 24 mg·kg(-1) markedly attenuated the inflammatory cell numbers in the BALF, decreased NF-κB p65 and COX-2 expression, and improved SOD activity, and inhibited MPO activity. The histological changes of the lungs were also significantly improved. The results indicated that G. biloba extract has a protective effect on LPS-induced acute lung injury in mice. The protective mechanism of G. biloba extract may be partly attributed to the inhibition of NF-κB p65 and COX-2 activation.
Acute Lung Injury ; chemically induced ; drug therapy ; metabolism ; Animals ; Bronchoalveolar Lavage Fluid ; cytology ; Cell Count ; Cyclooxygenase 2 ; genetics ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Gene Expression ; drug effects ; Ginkgo biloba ; chemistry ; Interleukin-1beta ; analysis ; Interleukin-6 ; analysis ; Lipopolysaccharides ; Lung ; immunology ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Peroxidase ; metabolism ; Phytotherapy ; Plant Extracts ; pharmacology ; Pulmonary Edema ; Superoxide Dismutase ; metabolism ; Transcription Factor RelA ; genetics ; metabolism ; Tumor Necrosis Factor-alpha ; analysis

Oxidative stress plays critical roles in airway inflammation that is usually accompanied by increased vascular permeability and plasma exudation. VEGF increases vascular permeability and leads to airway inflammation. In addition, VEGF has been shown to enhance receptor activator of NF-kappaB (RANK) expression in endothelial cells. An aim of the study was to determine the potential role of antioxidant in the regulation of RANK expression in murine model of asthma. We have used a C57BL/6 mouse model of allergic asthma to evaluate the effect of L-2-oxothiazolidine-4-carboxylic acid (OTC), a prodrug of cysteine, which acts as an antioxidant, and VEGF receptor inhibitor on RANK mRNA expression. The mice develop the following pathophysiological features of asthma in the lungs: increased expression of RANK mRNA, increased number of inflammatory cells of the airways, increased vascular permeability, and increased levels of VEGF. Administration of OTC and VEGF receptor inhibitor markedly reduced plasma extravasation and VEGF levels in allergen-induced asthmatic lungs. We also showed that the increased RANK mRNA expression at 72 h after ovalbumin inhalation were reduced by the administration of OTC or VEGF receptor inhibitor. The results indicate that OTC and VEGF receptor inhibitor which inhibit up-regulation of VEGF expression modulate RANK expression that may be in association with the regulation of vascular permeability, and suggest that VEGF may regulate the RANK expression. These findings provide a crucial molecular mechanism for the potential use of antioxidants to prevent and/or treat asthma and other airway inflammatory disorders.
Vascular Endothelial Growth Factor A/analysis/antagonists & inhibitors/metabolism ; Thiazolidines ; Thiazoles/*pharmacology ; Reverse Transcriptase Polymerase Chain Reaction ; Receptors, Vascular Endothelial Growth Factor/antagonists & inhibitors ; Receptors, Tumor Necrosis Factor/genetics/*metabolism ; Receptors, Cytoplasmic and Nuclear/genetics/*metabolism ; Reactive Oxygen Species/metabolism ; RNA, Messenger/genetics/metabolism ; Pyrrolidonecarboxylic Acid ; Proto-Oncogene Proteins c-akt/metabolism ; Protein Kinase Inhibitors/pharmacology ; Prodrugs/pharmacology ; Phosphorylation/drug effects ; Ovalbumin/immunology ; Osteoprotegerin ; Mice, Inbred C57BL ; Mice ; Immunohistochemistry ; Glycoproteins/genetics/*metabolism ; Gene Expression/drug effects ; Female ; Capillary Permeability/drug effects ; Bronchoalveolar Lavage Fluid/chemistry/cytology ; Blotting, Western ; Asthma/*drug therapy/immunology/metabolism ; Antioxidants/*pharmacology ; Animals