BACKGROUND/AIMS: Role of autophagy in neutrophil function and the association of autophagy and autophagy related (ATG) gene polymorphisms with asthma susceptibility were suggested. In this study, we investigated the genetic association of ATG5 and ATG7 polymorphisms with asthma risk, severity and neutrophilic airway inflammation. METHODS: We recruited 408 asthma patients and 201 healthy controls. Sputum neutrophil counts were determined by H&E staining. Serum interleukin 8 (IL-8) levels were measured by enzyme-linked immunosorbent assay (ELISA). Genetic polymorphisms of ATG5 (-769T>C, -335G>A, and 8830C>T) and ATG7 (-100A>G and 25108G>C) were genotyped. The functional activities of ATG5 -769T>C and -335G>A variants were investigated by luciferase reporter assays. RESULTS: No associations of ATG5 and ATG7 polymorphisms with asthma susceptibility and severity were found. ATG5 -769T>C and -335G>A were in complete linkage disequilibrium. In the asthma group, GA/AA genotypes at ATG5 -335G>A were associated with higher neutrophil counts in sputum (p < 0.05); CC/TT genotype at ATG5 8830C>T associated with lower FEV1% predicted value (p < 0.05). DNA fragments containing ATG5 -769T and -335G alleles had higher promoter activities compared to those with -769C and -335A in both human airway epithelial cells (A549, p < 0.01) and human mast cell (HMC-1, p < 0.001). GG and CC genotype at ATG7 -100A>G and 25108G>C were significantly associated with high serum levels of IL-8 (p < 0.05 for both variants). CONCLUSIONS: Genetic polymorphisms of ATG5 and ATG7 could contribute to neutrophilic airway inflammation in the pathogenesis of adult asthma.
Adolescent ; Adult ; Asthma/blood/*genetics/immunology/pathology ; Autophagy/*genetics ; Autophagy-Related Protein 5/*genetics ; Autophagy-Related Protein 7/*genetics ; Case-Control Studies ; Cell Line ; Female ; Gene Frequency ; Genes, Reporter ; Genetic Predisposition to Disease ; Haplotypes ; Heterozygote ; Homozygote ; Humans ; Interleukin-8/blood ; Male ; Middle Aged ; Neutrophil Infiltration/*genetics ; Neutrophils/immunology/metabolism/*pathology ; Phenotype ; *Polymorphism, Single Nucleotide ; Promoter Regions, Genetic ; Risk Factors ; Severity of Illness Index ; Transfection ; Young Adult

OBJECTIVETo study the effects of 1,25-(OH)(2)D(3) on airway remodeling and expression of high mobility group box 1 (HMGB1) and IL-17 in asthmatic mice.

METHODSFifty female mice were randomly divided into 5 groups: control, asthma, low-dose, middle-dose, and high-dose intervention groups (n=10 each). Asthma was induced by intraperitoneal injections of ovalbumin (OVA) and aerosol inhalation of OVA solution. The low-dose, middle-dose, and high-dose intervention groups were administered with 1,25-(OH)(2)D(3) solution at the dosage of 1, 4 and 10 μg/kg respectively by intraperitoneal injections before asthma challenge. The airway structural changes were assessed by hematoxylin and eosin staining. mRNA expression levels of HMGB1 and IL-17 in the lung tissues were evaluated by RT-PCR. The protein levels of HMGB1 and IL-17 in the lung tissues were observed by immunohistochemistry.

RESULTSThe airway wall thickness, protein and mRNA expression levels of HMGB1 and IL-17 were higher in the untreated asthma group than in the control group (P<0.05). The airway wall thickness, protein and mRNA expression levels of HMGB1 and IL-17 were lower in the middle-dose and low-dose intervention groups than in the untreated asthma group, and the middle-dose intervention group demonstrated lower airway wall thickness, protein and mRNA expression levels of HMGB1 and IL-17 than in the low-dose intervention group (P<0.05). However, the airway wall thickness, protein and mRNA expression levels of HMGB1 and IL-17 in the high-dose intervention group were higher than in the untreated asthma group (P<0.05).

CONCLUSIONSHMGB1 and IL-17 may be involved in the airway remodeling process in asthmatic mice. A moderate amount of HMGB1 and IL-17 may be involved in the airway remodeling process in asthmatic mice. A moderate amount of 1,25-(OH)(2)D(3) can improve the airway remodeling, but a higher dose of 1,25-(OH)(2)D(3) may affect adversely the airway remodeling process.

Airway Remodeling ; drug effects ; Animals ; Asthma ; drug therapy ; metabolism ; pathology ; Calcitriol ; pharmacology ; Dose-Response Relationship, Drug ; Female ; HMGB1 Protein ; analysis ; genetics ; physiology ; Interleukin-17 ; analysis ; genetics ; physiology ; Lung ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C

Airway remodeling is a key characteristic of chronic asthma, particularly in patients with a fixed airflow limitation. The mechanisms underlying airway remodeling are poorly understood, and no therapeutic option is available. The Wnt/beta-catenin signaling pathway is involved in various physiological and pathological processes, including fibrosis and smooth muscle hypertrophy. In this study, we investigated the roles of Wnt/beta-catenin signaling in airway remodeling in patients with asthma. Wnt7a mRNA expression was prominent in induced sputum from patients with asthma compared with that from healthy controls. Next, we induced a chronic asthma mouse model with airway remodeling features, including subepithelial fibrosis and airway smooth muscle hyperplasia. Higher expression of Wnt family proteins and beta-catenin was detected in the lung tissue of mice with chronic asthma compared to control mice. Blocking beta-catenin expression with a specific siRNA attenuated airway inflammation and airway remodeling. Decreased subepithelial fibrosis and collagen accumulation in the beta-catenin siRNA-treated mice was accompanied by reduced expression of transforming growth factor-beta. We further showed that suppressing beta-catenin in the chronic asthma model inhibited smooth muscle hyperplasia by downregulating the tenascin C/platelet-derived growth factor receptor pathway. Taken together, these findings demonstrate that the Wnt/beta-catenin signaling pathway is highly expressed and regulates the development of airway remodeling in chronic asthma.
Adult ; Aged ; *Airway Remodeling ; Animals ; Asthma/genetics/metabolism/*pathology ; Chronic Disease ; Female ; Fibrosis ; Gene Expression Regulation ; Humans ; Lung/metabolism/*pathology ; Male ; Mice, Inbred BALB C ; Middle Aged ; RNA Interference ; RNA, Messenger/genetics ; RNA, Small Interfering/genetics ; Wnt Proteins/genetics ; *Wnt Signaling Pathway ; beta Catenin/genetics/metabolism

OBJECTIVETo determine the changes in the expression of leptin and its receptor in the lungs of mice with varying degrees of asthma before and after budesonide treatment.

METHODSForty Balb/c mice were randomly assigned into 4 groups with 10 animals in each. One group received no treatment (control group) and the other groups were challenged with either nebulized ovalbumin (OVA) for three days (3-day group) or seven days (7-day group), or with nebulized ovalbumin followed by budesonide administration (treatment group). Changes in airway inflammation were observed using hematoxylin-eosin staining. The protein and mRNA levels of leptin and its receptor in lung tissues were determined using immunohistochemistry/Western blot and real-time PCR, respectively.

RESULTSThe two asthmatic groups showed more significant pathological changes in the airway than the control and the treatment groups. Mice that were challenged by OVA for seven days showed more marked pathological changes in the airway compared with mice challenged by OVA for three days. The protein and mRNA levels of leptin in the lung tissues of the 3-day group were significantly higher than those of the control group (P<0.01), but significantly lower than those of the 7-day group (P<0.01). The protein levels of leptin receptor in the lung tissues of the 3-day group were significantly lower than those of the control group (P<0.01). The treatment group showed increased protein levels of leptin receptor compared with the 7-day group (P<0.01). No significant difference was noted between the four groups with respect to the mRNA levels of leptin receptor in the lung tissues.

CONCLUSIONSLeptin is highly expressed whereas its receptor is lowly expressed in the lung tissues of asthmatic mice. Budesonide can increase the expression of leptin receptor, but has no significant impact on the expression of leptin.

Animals ; Asthma ; drug therapy ; metabolism ; pathology ; Blotting, Western ; Budesonide ; pharmacology ; Immunohistochemistry ; Leptin ; analysis ; genetics ; Lung ; chemistry ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; RNA, Messenger ; analysis ; Receptors, Leptin ; analysis ; genetics

OBJECTIVETo study the correlation between airway inflammation and osteopontin (OPN) level in the lung tissue, and to study the effect of dexamethasone (DXM) on OPN expression.

METHODSFifty mice were randomly divided into 5 groups: normal control, ovalbumin (OVA)-challenged asthma groups (OVA inhalation for 1 week or 2 weeks) and DXM-treated asthma groups (DXM treatment for 1 week or 2 weeks). The mice were sensitized and challenged with OVA to prepare mouse model of acute asthma. Alterations of airway inflammation were observed by haematoxylin-eosin staining. Serum level of OVA-sIgE was evaluated using ELISA. OPN expression in the lung tissue was located and measured by immunohistochemistry and Western blot respectively. OPN mRNA level in the lung tissue was detected by real-time PCR.

RESULTSThe asthma groups showed more pathological changes in the airway than the normal control and the DXM-treated groups. Compared with the OVA-challenged 1 week group, the pathological alterations increased in the OVA-challenged 2 weeks group. The level of OVA-sIgE in serum increased in the asthma groups compared with the control and the DXM groups (P<0.01). Serum OVA-sIgE sevel increased more significantly in the OVA-challenged 2 weeks group compared with the OVA-challenged 1 week group (P<0.01). OPN protein and mRNA levels were significantly raised in the asthma groups compared with the normal control and the DXM groups (P<0.01), and both levels increased more significantly in the OVA-challenged 2 weeks group compared with the OVA-challenged 1 week group (P<0.01).

CONCLUSIONSThe increased OPN expression in the lung tissue is associated with more severe airway inflammation in asthmatic mice, suggesting that OPN may play an important role in the pathogenesis of asthma. DXM can alleviate airway inflammation possibly by inhibiting OPN production.

Animals ; Asthma ; drug therapy ; metabolism ; pathology ; Dexamethasone ; therapeutic use ; Enzyme-Linked Immunosorbent Assay ; Female ; Immunoglobulin E ; blood ; Lung ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C ; Osteopontin ; analysis ; genetics ; physiology ; Ovalbumin ; immunology

OBJECTIVETo study the effects of suplatast tosilate (IPD) on the airway inflammation and expression of interleukin-5 in asthmatic rats.

METHODSFifty adult male Sprague-Dawley rats (4-week- old) were randomly assigned to five groups: placebo control, untreated asthma, budesonide(BUD)-treated asthma , early or late IPD intervention group (n=10 rats each). Asthmatic mode was prepared by ovalbumin sensitizion and challenge. Inflammatory cells and the percentage of EOS were detected in bronchoalveolar lavage fluid (BALF). The lung tissues were removed to detect the lung histomorphology. Gene expression of IL-5 was measured by reverse transcription-polymerase chain reaction (RT-PCR). Levels of interleukin 5 (IL-5) in BALF were measured using ELISA.

RESULTSThe inflammatory cells and the percentage of EOS in BALF, IL-5 levels in BALF and IL-5 mRNA expression in the lung tissues were obviously higher in the untreated asthma group than the control group (P<0.05), while the parameters in the IPD or BUD-treated asthma groups were significantly lower than the untreated asthma group (P<0.05).

CONCLUSIONSIPD treatment can alleviate airway inflammation in asthmatic rats, possibly through inhibiting IL-5 mRNA transcripts.

Animals ; Arylsulfonates ; therapeutic use ; Asthma ; drug therapy ; immunology ; pathology ; Eosinophils ; drug effects ; Interleukin-5 ; analysis ; antagonists & inhibitors ; genetics ; Lung ; metabolism ; pathology ; Male ; Rats ; Rats, Sprague-Dawley ; Sulfonium Compounds ; therapeutic use

OBJECTIVETo investigate the roles of signal transduction and activator of transcription 6 (STAT6) and orosomucoid 1-like 3 (ORMDL3) in airway remodeling among asthmatic mice and to observe the effects of budesonide (BUD) on their expression.

METHODSThirty BALB/c mice were randomly divided into control, asthma, and BUD intervention group. The mice were sensitized and challenged with ovalbumin (OVA) to establish a mouse model of asthma. The BUD intervention group received aerosol inhalation of BUD dissolved in normal saline 30 minutes before each OVA challenge, while normal saline was used instead of OVA solution in the control group. The pathological changes in the airway were observed by hematoxylin-eosin staining and Masson staining. The interleukin-13 (IL-13) level in lung homogenate was measured by enzyme-linked immunosorbent assay. The mRNA expression of STAT6 and ORMDL3 was measured by RT-PCR.

RESULTSThe asthma group showed more pathological changes in the airway than the control and BUD intervention groups, and the BUD intervention group had reduced pathological changes in the airway compared with the asthma group. The asthma and BUD intervention groups had significantly higher IL-13 levels and mRNA expression of STAT6 and ORMDL3 than the control group (P<0.05), and these indices were significantly higher in the asthma group than in the BUD intervention group (P<0.05). The Pearson correlation analysis showed that STAT6 mRNA expression was positively correlated with ORMDL3 mRNA expression (r=0.676, P=0.032).

CONCLUSIONSSTAT6 and ORMDL3 may be involved in the airway remodeling of mice, and BUD can reduce airway remodeling in asthmatic mice, possibly by down-regulating mRNA expression of STAT6 and ORMDL3.

Airway Remodeling ; drug effects ; Animals ; Asthma ; drug therapy ; pathology ; Budesonide ; pharmacology ; Down-Regulation ; Female ; Gene Expression Regulation ; drug effects ; Interleukin-13 ; analysis ; Lung ; metabolism ; Membrane Proteins ; genetics ; Mice ; Mice, Inbred BALB C ; STAT6 Transcription Factor ; genetics

OBJECTIVETo investigate the effects of low-concentration ozone exposure on the percentage of CD4(+)CD25(high)Foxp(3+) regulatory T cells and the mRNA expression of transcription factor Foxp3 in asthmatic rats.

METHODSSixty male Wistar rats were randomly divided into 4 groups (n = 15 for each): normal control group, ovalbumin (OVA) exposure group, ozone exposure group, and OVA+ozone exposure group. The OVA exposure group was sensitized and challenged with OVA to establish an asthma model; the normal control group inhaled aerosolized saline; the ozone exposure group inhaled low-concentration ozone; the OVA+ozone exposure group inhaled low-concentration ozone before being challenged with aerosolized OVA every day. The percentage of CD4(+)CD25(high)Foxp(3+) regulatory T cells in CD4(+) T cells was determined by flow cytometry. The levels of interferon-γ (INF-γ) and interleukin 4 (IL-4) in peripheral blood and lung tissue were measured by enzyme-linked immunosorbent assay. The mRNA expression of Foxp3 in lung tissue was measured by PCR.

RESULTSThe percentages of CD4(+)CD25(high)Foxp(3+) regulatory T cells in OVA exposure group (6.12±1.03%) and ozone exposure group (5.87±1.26%) were significantly lower than that in normal control group (9.85±1.34%), and the percentage of CD4(+)CD25(high)Foxp(3+) regulatory T cells in OVA+ozone exposure group (3.31±0.85%) was significantly lower than those in normal control group and OVA exposure group (P < 0.01). The levels of IL-4 in plasma and lung tissue in OVA exposure group (plasma: 21.83±5.12 ng/L; lung tissue: 0.89±0.13 ng/L) were significantly higher than those in normal control group (plasma: 10.58±2.73 ng/L; lung tissue: 0.32±0.11 ng/L) (P < 0.01). The levels of IL-4 in plasma and lung tissue in OVA+ozone exposure group (plasma: 35.47±7.24 ng/L; lung tissue: 1.50±0.42 ng/L) were significantly higher than those in normal control group and OVA exposure group (P < 0.01). The levels of INF-γ in plasma and lung tissue in OVA exposure group (plasma: 61.78±23.45 ng/L; lung tissue: 0.69±0.21 ng/L] were significantly lower than those in normal control group [plasma: 158.89±60.23 ng/L; lung tissue: 1.86±0.29) (P < 0.01). The levels of INF-γ in plasma and lung tissue in OVA+ozone exposure group (plasma: 10.28±2.63 ng/L; lung tissue: 0.41±0.12 ng/L) were significantly lower than those in normal control group and OVA exposure group (P < 0.01). The mRNA expression of Foxp3 was significantly lower in the OVA+ ozone exposure group than in the normal control group (P < 0.05).

CONCLUSIONLow-concentration ozone exposure may decrease the number of CD4(+)CD25(high)Foxp(3+) regulatory T cells and inhibit the mRNA expression of Foxp3 to promote Th1/Th2 imbalance in asthmatic rats, suggesting that ozone exposure may be one of factors that induce asthma attack.

Animals ; Asthma ; metabolism ; Environmental Exposure ; Flow Cytometry ; Forkhead Transcription Factors ; genetics ; metabolism ; Interferon-gamma ; metabolism ; Interleukin-4 ; metabolism ; Lung ; metabolism ; pathology ; Male ; Ozone ; adverse effects ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar ; T-Lymphocytes, Regulatory ; drug effects ; metabolism ; Th1-Th2 Balance

OBJECTIVETo investigate the therapeutic value and possible mechanism of diammonium glycyrrhizinate (DG) in treatment of airway remodeling in a murine model of chronic asthma.

METHODSThirty male BALB/C mice were randomly divided into control group, OVA+DG group and OVA group (n=10). HE staining was used to observe the pathological changes, and Masson's staining was used to detect and measure collagen deposition. Alpha-SMA and PPARγ mRNA expressions were analyzed by RT-PCR, and the protein expressions of α-SMA and PPARγ were measured by Western blotting.

RESULTSAfter 75 days of OVA sensitization and challenge, obvious pathological changes occurred in the lung tissues, which was more severe in OVA group than in OVA+DG group. Collagen deposition was significantly increased after OVA stimulation, but was obviously milder in OVA+DG group than in OVA group. OVA-induced up-regulation of α-SMA was notably attenuated by DG injection. The expression of PPARγ was markedly down-regulated after OVA stimulation but was substantially enhanced after DG intervention.

CONCLUSIONDG can inhibit airway smooth muscle proliferation possibly through up-regulation of PPARγ in a murine model of chronic asthma.

Actins ; genetics ; metabolism ; Airway Remodeling ; drug effects ; Animals ; Anti-Inflammatory Agents ; pharmacology ; Asthma ; metabolism ; pathology ; Cell Proliferation ; drug effects ; Collagen ; metabolism ; Glycyrrhizic Acid ; pharmacology ; Lung ; metabolism ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Muscle, Smooth ; pathology ; Ovalbumin ; pharmacology ; PPAR gamma ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Random Allocation ; Up-Regulation

Neuropilin 1 (NP1) is a part of essential receptor complexes mediating both semaphorin3A (SEMA3A) and vascular endothelial growth factor (VEGF) which is one of important mediators involved in the pathogenesis of asthma. Therefore, it is possible that SEMA3A plays a role in the pathogenesis of asthma through attenuation of VEGF-mediated effects. In the present study, we aimed to evaluate expression levels of SEMA3A and NP1 using induced sputum of asthmatics and a murine model of asthma. Firstly, SEMA3A and NP1 expressions in induced sputum of asthmatics and SEMA3A and NP1 expression on bronchoalveolar lavage (BAL) cells and lung homogenates of asthmatic mice were determined. Then we evaluated the immunolocalization of VEGF receptor 1 (VEGFR1), VEGF receptor 2 (VEGFR2), and NP1 expressions on asthmatic mice lung tissue and their subcellular distributions using fibroblast and BEAS2B cell lines. Sputum SEMA3A and NP1 expressions were significantly higher in asthmatics than controls. Similarly, SEMA3A and NP1 expressions on BAL cells and lung homogenates were significantly elevated in asthmatic mice compared to control mice. Immunohistochemical analysis showed that VEGFR1, VEGFR2, and NP1 expressions were also uniformly increased in asthmatic mice. Our observations suggest that SEMA3A and NP1 may play important roles in the pathogenesis of asthma.
Animals ; Asthma/metabolism/pathology/*physiopathology ; Bronchoalveolar Lavage Fluid/cytology ; Cell Line ; Disease Models, Animal ; Female ; Fibroblasts/metabolism ; *Gene Expression Regulation ; Immunohistochemistry ; Lung/metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Neuropilin-1/*genetics/metabolism ; Semaphorin-3A/*genetics/metabolism ; Sputum/metabolism ; Vascular Endothelial Growth Factor Receptor-1/metabolism ; Vascular Endothelial Growth Factor Receptor-2/metabolism