ObjectiveTo investigate the effects of BCG intervention on the airway remodeling and serum hypoxia-inducible factor-1 alpha(HIF-1α)expression in bronchial asthma rats.

MethodsThirtySD rats were randomly divided into the control group, asthma group and BCG treatment group(10 rats each group).The asthma group were intraperitoneally injected with 10% egg albumin(OVA)combined with aluminum hydroxide mixture for sensitization, and then stimulated by 1% OVA ultrasonic atomization inhalation to establish bronchial asthma model.The control group were treated with the same establishing model method, but at the corresponding time point, 0.9% sodium chloride solution was used to replace the sensitizer, and intraperitoneal injection and ultrasonic atomization inhalation were performed.The modeling method in BCG treatment group were the same as that of the asthma group, and the intradermal injection of 0.025 mg of BCG before half an hour of atomization was performed daily for intervention treatment.The inter-group variables were analyzed using Pearson correlation analysis method.The serum samples were collected after 24 h of last stimulation in three groups, and the contents of HIF-1α were detected using ELISA.After the rats were sacrificed, the trachea and lung histopathology sections were made to observe the airway inflammation and tracheal remodeling.The image analysis software was used to measure the internal diameter circumference(Pi), bronchial tube wall area(WAt)and total area of bronchial smooth muscle(WAm).

ResultsThe structures of alveoli, trachea and blood vessels in control group were normal.In the asthma group, the alveolar wall significantly thickened, mucus remained in the trachea cavity, and intra-alveolar hemorrhage was partially observed.The overall structure of lung tissues in BCG treatment group tended to be normal.The serum HIF-1α content in asthma group increased compared with the control group, and the serum HIF-1 content decreased after BCG intervention(P < 0.01).The HIF-1α was positively correlated with bronchial wall thickness(WAt/Pi)and bronchial smooth muscle thickness(WAm/Pi)(P < 0.01).

ConclusionsAfter BCG intervention treatment, the airway remodeling alleviates in bronchial asthma rats, and the effects may be by inhibiting HIF-1α expression to play.