Effects of vasoactive intestinal peptide on airway inflammation and Th17/Treg balance in asthmatic mice / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the effects of vasoactive intestinal peptide (VIP) on the airway inflammation and its regulatory effect on Th17/Treg imbalance in asthmatic mice.</p><p><b>METHODS</b>A total of 30 BALB/c mice were equally and randomly divided into three groups: control, asthma, and VIP. An acute asthmatic mouse model was established by sensitization and challenge with ovalbumin (OVA). The control group received normal saline instead of OVA. Before the challenge with OVA, the VIP group was administered VIP (20 μg/mL) by aerosol inhalation for 30 minutes. The bronchoalveolar lavage fluid (BALF) and the lung tissue were collected from mice. The pathological changes in the lung tissue were observed by hematoxylin and eosin staining. The levels of Th17/Treg-related cytokines in BALF were measured by enzyme-linked immunosorbent assay. The expression of retinoid-related orphan receptor gamma t (RORγt) and forkhead box P3 (Foxp3) were measured by real-time fluorescence quantitative PCR and immunohistochemistry.</p><p><b>RESULTS</b>The histopathological results showed that the VIP group had milder symptoms of airway inflammation than the asthma group. The level of IL-17 in BALF in the asthma group was significantly higher than that in the control group and the VIP group (P<0.01), but the level of IL-17 in the control group was significantly lower than that in the VIP group (P<0.01). The level of IL-10 in BALF in the asthma group was significantly lower than that in the control group and the VIP group (P<0.01, but the level of IL-10 in the VIP group was significantly higher than that in the control group (P<0.01). The asthma group showed significantly higher expression levels of RORγt mRNA and protein in the lung tissue and significantly lower expression levels of Foxp3 mRNA and protein than the control group (P<0.01). The VIP group had significantly lower expression levels of RORγt mRNA and protein in the lung tissue and significantly higher expression levels of Foxp3 mRNA and protein than the asthma group (P<0.05).</p><p><b>CONCLUSIONS</b>The Th17/Treg imbalance may be closely related to the airway inflammation in asthmatic mice. VIP can improve airway inflammation by regulating the Th17/Treg imbalance in asthmatic mice.</p>

Clinical analysis of hemolytic-uremic syndrome associated with Streptococcus pneumoniae serotype 3 infection in a child / 中华儿科杂志

<p><b>OBJECTIVE</b>To study the clinical characteristics of Streptococcus pneumonia-associated hemolytic uremic syndrome (SP-HUS) in children.</p><p><b>METHOD</b>Clinical and laboratory data of a pediatric case of SP-HUS were retrospectively analyzed and the key points of diagnosis and therapy were reviewed.</p><p><b>RESULT</b>An 18-month old girl was admitted with chief complaint of fever and cough for 5 days combined with mild labored breath. Breath sound was found weakened in right lung with lower lobe dullness on percussion. Laboratory tests revealed: WBC 3.7×10(9)/L, Hb 83 g/L, PLT 11×10(9)/L, C-reactive protein (CRP) > 180 mg/L. Morphological study of the RBCs showed marked anisocytosis and schistocytosis. Urinalysis showed 42.66 RBCs per high-power field, occult blood (+++), proteinura (++++). Streptococcus pneumoniae was isolated from blood, pleural fluid and sputum. Serotyping with simplified chessboard system was 3. The direct Coombs test was positive. Serum complement levels (C3 and C4) were depressed at 0.699 g/L, 0.064 g/L, respectively. Chest X-ray showed pleural effusion and infection of the right hemothorax. The computerized tomographic scan of the chest revealed pneumatoceles in the right lower lobe. The diagnosis on admission we considered was SP-HUS. Intravenous antibiotic therapy (vancomycin + cefoperazone/sulbactam) was administered. The renal replacement theraphy was administered to maintain electrolyte and fluid balances and adequate nutrition. Transfusions of washed red blood cells were administered to correct the anemia. One month after admission the patient was good with recovery. Liver and renal function recovered and the pneumonia was resolving, anemia and platelets were corrected. The direct Coombs test turned to be negative. Serum complement levels (C3 and C4) were normal. After 3-month follow-up, no clinical anomalies were detected.</p><p><b>CONCLUSION</b>SP-HUS should be suspected when the following occurs in the context of pneumococcal infections: microangiopathic hemolytic anemia, thrombocytopenia, acute renal failure and a positive Coombs test result. Serotype 3 of SP was associated with HUS.</p>

Epidemiological characteristics of Mycoplasma pneumoniae pneumonia in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the epidemiological characteristics of Mycoplasma pneumoniae pneumonia (MPP) in children, and to provide a basis for diagnosis and treatment.</p><p><b>METHODS</b>The serum level of Mycoplasma pneumoniae antibody IgM (MP-IgM) was measured by enzyme-linked immunosorbent assay for 3156 hospitalized children with confirmed community acquired pneumonia from February 2011 to January 2012. The antigens of seven respiratory viruses were detected in the nasopharyngeal secretions of children with MPP.</p><p><b>RESULTS</b>MP-IgM was detected in 427 of the 3156 patients, with a positive rate of 13.53%. The infection rate in female patients was significantly higher than in male patients (16.30% vs 11.70%; P<0.01). The MP-IgM detection rates were 3.6%, 12.5%, 19.2%, and 24.4% in children aged under 1 year, 1-3 years, 3-6 years and 6-14 years respectively (P<0.01), and the total MP-IgM detection rate in children aged under 3 years was significantly lower than in children over 3 years (P<0.01). The MP-IgM detection rate varied with the seasons and was significantly higher in summer and autumn than in winter and spring (19.18% vs 9.61%; P<0.01). Of the 427 MP-IgM-positive children, 60 (14.1%) were infected with respiratory viruses, and the highest proportion of which was respiratory syncytial virus.</p><p><b>CONCLUSIONS</b>MPP is sporadic throughout the whole year, with a higher incidence in summer and autumn. MPP occurs mostly in preschool and school-age children, and there is mixed infection of MP and respiratory viruses.</p>

Viral etiology of acute respiratory infection in children from Wenzhou between 2007 and 2008 / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the viral etiology of acute respiratory infection (ARI)in children from Wenzhou, Zhejiang between 2007 and 2008.</p><p><b>METHODS</b>The nasopharyngeal aspirate samples were obtained from 5 097 hospitalized children with ARI. Seven common respiratory viruses, including respiratory syncytial virus (RSV), influenza virus A and B, parainfluenza viruses 1, 2 and 3 and adenovirus, were detected using direct immunofluorescence.</p><p><b>RESULTS</b>Viral agents were identified in 2 209 cases (43.3%).Of the 2 209, RSV was the most frequent (78.1%), followed by parainfluenza 3 (12.4%), influenza virus A (3.0%), adenovirus (2.8%), parainfluenza 1 (1.7%), influenza B (0.5%) and parainfluenza 2 (0.3%). The infants at ages of <3 months and <6 months had higher detection rate of viruses (53.6% and 49.2%, respectively). A highest detection rate of viruses was found in winter.</p><p><b>CONCLUSIONS</b>RSV is the leading pathogen of ARI in children from Wenzhou, Zhejiang between 2007 and 2008. The children at age of less than 6 months are susceptible to respiratory viruses. The viral activity peaks in winter.</p>

Clinical analysis of 234 cases with congenital malformations of respiratory system / 中华儿科杂志

<p><b>OBJECTIVE</b>To explore clinical characteristics, radiographic findings and diagnostic methods of patients with congenital malformations of respiratory system for enhancing the diagnosis of congenital malformations of respiratory system in children.</p><p><b>METHOD</b>Totally 234 patients with congenital malformations of respiratory system were chosen from the inpatient department of Yuying Children's Hospital Affiliated to Wenzhou Medical College from July 2003 to June 2008. The clinical presentations and radiographic findings of these children were analyzed.</p><p><b>RESULT</b>Of the 234 patients with congenital malformations of respiratory system, the age at diagnosis was between the first day and 14 years of age, mean age was 1.12 years. The main symptoms were persistent laryngeal stridor, recurrent wheezing, recurrent respiratory tract infections and dyspnea. Through the use of chest X-ray, spiral CT 3D reconstructions, fiberoptic bronchoscopy and other laboratory techniques, 213 cases were diagnosed as having single malformation and 21 cases were found to have multiple malformations. Of the 213 cases with single malformation, 97 cases had laryngeal malformation (congenital laryngeal stridor in 90 cases, congenital laryngeal webs in 5 cases and congenital laryngeal cyst in 2 cases), 35 cases had tracheal-bronchial malformation (congenital tracheobronchial stenosis in 17 cases, congenital abnormal bronchial origin in 7 cases, tracheobronchomalacia in 10 cases and tracheoesophageal fistula in 1 case), 43 cases had lung malformation (pulmonary sequestration in 5 cases, congenital lung cysts in 22 cases, congenital lobar emphysema in 1 case, agenesis of lung and hypoplasia of lung in 8 cases and congenital cystic adenomatoid malformation in 7 cases), 38 cases had diaphragm malformation, 28 cases had congenital tracheal-bronchial stenosis as confirmed by spiral CT 3D reconstructions and fiberoptic bronchoscopy. Ten cases with congenital abnormal bronchial origin were diagnosed with spiral CT 3D reconstructions. Laryngeal stridor and tracheobronchomalacia were diagnosed by fiberoptic laryngoscope and fiberoptic bronchoscopy. The accuracy rates of preoperative diagnosis through clinical and radiographic examinations of 37 cases with lung malformation and 36 cases with diaphragm malformation were 83.78% and 91.67%.</p><p><b>CONCLUSION</b>Congenital malformations of respiratory system are a group of diseases that are important for pediatric respiratory clinicians. Congenital malformations of respiratory system should be considered in children with persistent laryngeal stridor, recurrent wheezing, recurrent respiratory tract infections and dyspnea. The radiographic examination and respiratory endoscope play important roles in the diagnosis of congenital malformations of respiratory system.</p>

Role of external signal regulated kinase signal transduction pathway in airway remodeling of rats with asthma and regulation by glucocorticoids / 中华儿科杂志

<p><b>OBJECTIVE</b>Airway remodeling in asthma makes treatment of asthma very difficult, and study of its pathogenesis becomes very important. The present study aimed to explore the role of external signal regulated kinase (ERK) signal transduction pathway in airway remodeling in rats asthma model and regulatory effects of glucocorticoids on ERK signal transduction pathway and airway remodeling.</p><p><b>METHODS</b>Totally 80 male Sprague-Dawlay rats (6-8 weeks old, weighing about 120 g) were randomly divided into control groups (30 rats), asthma groups (30 rats) and treated groups [including a group intervened with dexamethasone (DM group) and budesonide (BUD group), each had 10 rats]. The rats were sensitized for inducing asthma by intraperitoneal injection of ovalbumin and Al (OH)(3) and were repeatedly exposed to aerosolized ovalbumin for 4, 8, or 12 weeks [respectively called 4, 8 or 12 wk asthma group (A4, A8 or A12 group), each had 10 rats]; and correspondingly control rats were intraperitoneally injected with 0.9% NaCl, then were repeatedly exposed to 0.9% NaCl for 4, 8, or 12 weeks [respectively called 4, 8 or 12 wk control group (C4, C8 or C12 group), each had 10 rats]; DM group rats were repeatedly exposed to aerosolized ovalbumin for 8 wk, and BUD group rats for 12 wk. Total bronchial wall thickness (Wat) and smooth muscle thickness (Wam) were measured by an image analysis system. Concentrations of PDGF-AB in serum were measured by sandwich ELISA. Phospho-ERK (P-ERK) and c-Fos were detected by immunohistochemical technique; lung tissue extracts were analyzed for phosphorylation of ERK by Western blotting.</p><p><b>RESULTS</b>Wat and Wam in all asthma groups were significantly higher than those in corresponding control groups (P < 0.01, respectively), those of the treated groups were significantly lower than asthma groups (P < 0.01). The concentrations of PDGF-AB in serum of asthma groups [(228 +/- 18) pg/ml, (293 +/- 77) pg/ml, (225 +/- 66) pg/ml for A4, A8, A12 groups, respectively] were all significantly higher than those of the control groups [(160 +/- 14) pg/ml, (165 +/- 29) pg/ml and (164 +/- 27) pg/ml for C4, C8, C12 group, respectively] (P < 0.01 or P < 0.05); the value of DM group [(157 +/- 46) pg/ml] was significantly lower than that of the group A8 (P < 0.01), no significant difference was found when the values of BUD group [(208 +/- 40) pg/ml] was compared with that of A12 group (P > 0.05). Mean absorbance values (by immunohistochemistry) of P-ERK and c-Fos in asthma groups were significantly higher than those in corresponding control groups (P < 0.01, respectively), DM group had a significantly lower value than group A8 (P < 0.01), BUD group had a significantly lower value than group A12 (P < 0.01); absorbance (by Western blot) of P-ERK in A4, A8, A12 group was significantly higher than that in C4 and C8 group, the value of DM group was significantly lower than that of group A8 (P < 0.01), and that of BUD group (1.8 +/- 0.2) was significantly lower than that of group A12 (P < 0.01).</p><p><b>CONCLUSION</b>Asthmatic rats have higher concentrations of PDGF-AB in serum and phosphorylation of ERK and c-Fos; glucocorticoids inhibit phosphorylation of ERK and c-Fos in asthmatic rats, and to some extent also inhibit Wat and Wam.</p>

Effect of Radix Astragali on signal transducer and activator of transcription activator-4 and its mRNA expression in a rat model of asthma / 中华儿科杂志

<p><b>OBJECTIVE</b>To study the effect of Radix Astragali (RA) on the expression of signal transducer and activator of transcription-4 (STAT4) and its mRNA in the bronchus of a rat model of asthma.</p><p><b>METHODS</b>Forty male SD rats were randomly divided into four groups: the control group, asthma group, high dosage of RA group and low dosage of RA group. In the experiment, the rat model of asthma was established by the ovalbumin (OVA) challenge methods. The lung tissue was gainedfrom the left lung, bronchoalveolar lavage fluid (BALF) was gained from the right lung. The eosinophils (EOS) numbers and differentiated cell numbers in BALF were counted by different counting fluids; the protein expressions of STAT4 were detected by immunohistochemistry; the mRNA expressions of STAT4 were detected by in situ hybridization.</p><p><b>RESULTS</b>(1) In the BALF of the asthma group, the absolute numbers of EOS, the ratios of EOS to the total cell numbers (EOS%) of asthma group [(35.81 +/- 7.30) x 10(7)/L, (8. 20 +/- 1.75)%] were all significantly higher than those of the control group [(1.51 +/- 1.04) x 10(7)/L, (0.70 +/- 0.48)%] (P < 0.01); the total cell numbers in BALF, the absolute numbers of EOS and EOS% of RA groups [(14.89 +/- 2.35) x 10(7)/L, (4.70 +/- 0.82)%; (10.98 +/- 1.81) x 10(7)/L, (3.56 +/- 0.53)%] were all significantly lower than those of asthma group (P < 0.01); (2) The concentration of IL-4 in BALF of asthma group (25.70 +/- 7.36) was significantly higher than that of the control group (8.55 +/- 2.97) (P < 0.01); the concentration of IL-4 of BALF of RA groups [(31.89 +/- 5.46), (35.26 +/- 6.03)] was significantly lower than that of asthma group (P < 0.01); the concentration of IL-12 of BALF of asthma group (16.10 +/- 3.38) was significantly lower than that of the control group (42.33 +/- 9.66) (P < 0.01); the concentration of IL-12 of BALF of the RA groups [(31.89 +/- 5.46), (35.26 +/- 6.03)] was significantly higher than that of the asthma group (P < 0.01); (3) Immunohistochemistry and in situ hybridization showed that the protein content of STAT4 and the STAT4 mRNA expression around the bronchus of asthma group [(0.096 +/- 0.012), (0.098 +/- 0.011)] were lower than those of the control group [(0.216 +/- 0.034), (0.228 +/- 0.032)], while those of RA groups [(0.176 +/- 0.012), (0.185 +/- 0.023); (0.183 +/- 0.011), (0.201 +/- 0.019)] were all significantly higher than that of the asthma group (P < 0.01), the airway smooth muscle cells, the pulmonary arterial smooth muscle cells and endothelial cells were the chief expression cells; (4) the STAT4 and the STAT4mRNA expression around the bronchus had positive correlation with the concentration of IL-12 in BALF while had negative correlation with the concentration of IL-4, absolute numbers of EOS in BALF.</p><p><b>CONCLUSIONS</b>RA has an inhibitory effect on airway inflammation cells infiltration such as EOS, it raises the STAT4 protein and its mRNA expression in the airway smooth muscle cells, the pulmonary arterial smooth muscle cells and endothelial cells, and the key mechanism may be that the IL-12 composition is increased.</p>

Detection of etiologic agents and antibiotic resistance in children with acute lower respiratory tract infection in Wenzhou City / 中国当代儿科杂志

<p><b>OBJECTIVE</b>The etiology of acute lower respiratory tract infection (LRTI) in children in Wenzhou City remains poorly defined. This study investigated the etiological agents responsible for acute LRTI and patterns of the antibiotic resistant bacterial pathogens in children with acute LRTI from Wenzhou City.</p><p><b>METHODS</b>Lower respiratory tract secretions were obtained from 454 children with acute LRTI (aged 1 month to 10 years, median age 6 months) within 24 hrs after admission for bacterial culture. Meanwhile respiratory viruses were detected by the Direct immunofluorescence (DIF) assay. The K-B method was applied for the drug susceptibility test.</p><p><b>RESULTS</b>Etiological agents were identified in 297 cases out of 454 patients (65.4%. Viral pathogens were identified in 229 cases (50.4%), bacteria in 135 cases (29.7%) and mixed viral-bacterial infections in 67 cases (14.8%). The isolating rate of Respiratory syncytial virus (RSV) was the highest (180 cases, 39.6%) in all of the samples. The isolating rates of other viral pathogens were as follows: Parainfluenza virus 3 type (PIV3) (6.6%), Adenovirus (2.2%), Influenza A (0.9%) and Influenza B (0.7%). Of the 135 strains of bacterial pathogens, 19 kinds of bacterial pathogens were isolated. The predominant isolate was Klebsiella pneumoniae (K. pneumoniae) (9.9%), followed by Escherichia coli (E.coli) (4.4%), Streptococcus pneumoniae (S. pneumoniae) (4.2%) and Staphylococcus aureus (S. aureus) (4.2%). The isolating rates of K. pneumoniae and E.coli with extended-spectrum beta-lactamases strains (ESBLs) positive were 42.2% and 65.0%, respectively. The pathogens isolated of the first 5 places in children with acute LRTI under six months were RSV, K. pneumoniae, PIV3, E.coli and S. aureus in turn. RSV, PIV3, S. pneumoniae, K. pneumoniae and E.coli were found to be the pathogens of the first 5 places in children with acute LRTI between six months and three years. The resistant rates of K. pneumoniae and E.coli to ampicillin were 97.8% and 75.0%, respectively. K. pneumoniae and E.coli with positive ESBLs were resistant to cephalosporin. The resistant rates of S. pneumoniae to erythromycin and penicilin were 100% and 68.4%, respectively. The resistant rates of S. aureus to erythromycin and penicillin were 94.7% and 89.5%, respectively.</p><p><b>CONCLUSIONS</b>RSV is the most common pathogen responsible for acute LRTI in children in Wenzhou City, followed by K. pneumoniae and PIV3. The rate of antibiotic resistance of common bacteria and the isolating rate of Gram-negative bacillus with ESBLs positive are high.</p>

Regulative mechanism of dexamethasone on Toll-like receptor 4 signal transduction of infant asthma rat / 中华儿科杂志

<p><b>OBJECTIVE</b>Eosinophilic airway inflammation is one of the basic characteristics of allergic asthma. Toll-like receptor is one of the most important innate immunity pattern recognition receptors. Glucocorticoids (GCS) are still the most effective treatment for asthma. However, few reports of studies on regulatory mechanism of GCS on the innate immunity system are available. The mechanism of effects of GCS on TLR4 is unclear. The present study aimed at understanding the effect of dexamethasone (DXM) on change of TLR4 and mechanism of regulatory effect of TLR4 on eosinophil (EOS) apoptosis.</p><p><b>METHODS</b>Twenty-seven Sprague-Dawley (SD) rats (age 28 to 42 days, body weight 120 to 180 gram) were randomly divided into the control group, asthma group and DXM group with 9 in each. Asthma model rats were sensitized with the mixture of ovalbumin (OVA, 1 mg) and Al (OH)(3), 100 mg on day 1 and day 8, repeatedly exposed to aerosolized OVA after day 15, once a day for three days and continued for 30 minutes at every time. During the sensitization stage, 100 microg/ml DXM were prepared with DXM group for every other day, and the same doses DXM were prepared for every day on the stage of challenge. The histopathological changes of lung tissues were observed with light microscope (LM). EOS and other inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted; the concentrations of OVA-sIgE in serum were measured by using "sandwich" ELISA; The expressions of TLR4 mRNA were determined by in situ hybridization, the apoptosis of EOS was detected by TUNEL.</p><p><b>RESULTS</b>(1) LM showed many inflammatory cells infiltration around the bronchi and blood vessels, bronchus mucus increased, airway epithelium damage and desquamation, and airway mucous plugs in asthma group, whereas DXM group showed significantly milder changes. (2) Inflammationary cells count in BALF of asthma group was significantly higher as compared to control group (P < 0.01); compared with asthma group, the total cell count, EOS absolute count and EOS% were all significantly decreased in DXM group [(2.14 +/- 0.10) x 10(9)/L, (4.78 +/- 1.23) x 10(7)/L, (2.17 +/- 0.25)%]. (3) Levels of OVA-sIgE in serum of asthma group [(83.40 +/- 6.80) microg/ml] were significantly higher than those of the control group [(14.38 +/- 4.25) microg/ml] (P < 0.01), while those of DXM group [(45.02 +/- 7.47) microg/ml] were significantly lower than asthma group (P < 0.0 1). (4) There were no significant differences in TLR4 mRNA detected by in situ hybridization between control group (24.71 +/- 0.85) and asthma group (25.81 +/- 3.56) (P > 0.05); but it significantly increased in DXM group (29.86 +/- 3.92) as compared to asthma group. (5) The percentages of apoptotic EOS in asthma group [(7.39 +/- 1.93)%] were significantly lower than those in control group [(9.06 +/- 1.52)%] (P < 0.01); and significantly higher in DXM group [(13.33 +/- 1.09)%] than in asthma group (P < 0.01). There were significantly positive correlations between TLR4 mRNA and the percentage of apoptotic EOS (r = 0.612, P < 0.01).</p><p><b>CONCLUSION</b>DXM can decrease OVA-sIgE level, induce EOS apoptosis, which may correlate with the activation of TLR4 signal transduction.</p>

Effect of achyranthes bidentata polysaccharides on signal transducer and activator of transcription 6 and its mRNA expression in a rat model of asthma / 中国应用生理学杂志

<p><b>AIM</b>To study the effect of achyranthes bidentata polysaccharides(ABPS) on the expression of signal transducer and activator of transcription 6 and its mRNA in bronchus of a rat model of asthma.</p><p><b>METHODS</b>Thirty male SD rats were randomly divided into three groups: the control group, asthma group and ABPS group. The total cell numbers, eosinophils (EOS) numbers and differentiated cell numbers in bronchoalveolar lavage fluid (BALF) were counted by different count fluids. The concentrations of IL-4 in serum and BALF were measured by sandwich ELISA. The protein expressions of STAT6 were detected by immunohistochemistry techniques. The mRNA expressions of STAT6 were detected by hybridization in situ.</p><p><b>RESULTS</b>(1) The total cell numbers in BALF, the absolute numbers of EOS, the ratios of eosinophils to the total cell numbers (EOS%) of asthma group were all significantly higher than those of the control group (P < 0.01). The total cell numbers in BALF, the absolute numbers of EOS and EOS% of ABPS group were all significantly lower than those of asthma group (P < 0.01). (2) The concentrations of IL-4 in BALF and serum of asthma group were significantly higher than those of control group (P < 0.01), while the concentrations of IL-4 in BALF and serum of ABPS group were significantly lower than those of asthma group. (3) Immunohistochemistry showed that the protein content of STAT6 around the bronchus of asthma group was significantly higher than that of the control group (P < 0.01), while that of ABPS group was significantly lower than that of asthma group , the epithelial cells were the chief expression cells; hybridization in situ showed that the mRNA expression of STAT6 around the bronchus of asthma group was significantly higher than that of the control group (P < 0.01), while that of ABPS group was significantly lower than that of asthma group , the epithelial cells were the chief expression cells.</p><p><b>CONCLUSION</b>STAT6 protein and STAT6 mRNA were found strongly expressed in rat asthma model, the epithelial cells were the chief expression cells. ABPS had an inhibitory effect on airway inflammation cells infiltration such as EOS, it significantly depressed STAT6 and its mRNA expression, thus reduced the synthesis of IL-4 might be key in modulating mechanism of asthma.</p>

Expression of signal transducer and activator of transcription 6 in rat asthma model and the modulatory effect of dexamethasone / 中华儿科杂志

<p><b>OBJECTIVE</b>To study the expression of signal transducer and activator of transcription 6 and its mRNA in rat asthma model and the modulatory effect of dexamethasone (DXM).</p><p><b>METHODS</b>Thirty male SD rats were randomly divided into three groups: the control group, asthma group and DXM group. The rats in each group were sacrificed 24 h after the last challenge. In the experiment, the rat model of asthma was established by ovalbumin (OVA) challenge method. The lung tissue was taken from the left lung, and bronchoalveolar lavage fluid (BALF) was collected from the right lung. The total cell numbers, eosinophils (EOS) count and differentiated cell counts in BALF were performed on different count fluids. The concentrations of IL-4 in serum and BALF were measured by using sandwich ELISA. The protein expressions of STAT6 were detected with immunohistochemical techniques. The mRNA expressions of STAT6 were detected with in situ hybridization.</p><p><b>RESULTS</b>(1) The total cell counts in BALF, the absolute counts of EOS, and the ratios of eosinophils to the total cell numbers (EOS%) of asthma group were all significantly higher than those of the control group (P < 0.01). The total cell counts in BALF, the absolute counts of EOS, and EOS% of DXM group were all significantly lower than those of asthma group (P < 0.01). (2) The concentrations of IL-4 in BALF and serum of asthma group [(25.7 +/- 7.4) ng/L, (34.2 +/- 10.5) ng/L] were significantly higher than those of control group [(8.6 +/- 3.0) ng/L, (12.1 +/- 2.9) ng/L] (P < 0.01). The concentrations of IL-4 in BALF and serum of DXM group were significantly lower than those of asthma group. (3) Immunohistochemistry showed that the protein content of STAT6 around the bronchus of asthma group (0.171 +/- 0.025) was significantly higher than that of the control group (0.082 +/- 0.022) (P < 0.01), while that of DXM group (0.114 +/- 0.013) was significantly lower than that of asthma group. The epithelial cells were the cells. In situ hybridization showed that the mRNA expression of STAT6 around the bronchus of asthma group (0.180 +/- 0.013) was significantly higher than that of the control group (0.091 +/- 0.012) (P < 0.01), while that of DXM group (0.114 +/- 0.010) was significantly lower than that of asthma group. (4) There was a significant correlation between the concentration of IL-4 in BALF, the content of STAT6 and STAT6 mRNA, respectively, in the epithelial cells of bronchus. There was a significant correlation between the absolute numbers of EOS and EOS% in BALF, the content of STAT6 and STAT6 mRNA, respectively, in the epithelial cells of bronchus.</p><p><b>CONCLUSIONS</b>STAT6 protein and STAT6 mRNA were found strongly expressed in rat asthma model and the epithelial cells were the chief expressing cells. Dexamethasone had an inhibitory effect on airway inflammatory cells infiltration. It significantly depressed STAT6 and mRNA expression. Which may be a key process in modulatory mechanism of asthma.</p>