Role of transforming growth factor β1 in airway remodeling of bronchial asthma rats exposed to aspergillusus fumigatus

Objective To investigate the effects of transforming growth factor β1 (TGF-β1) on bronchial asthma (asthma) rats exposed to aspergillus fumigatus. Methods Thirty-two healthy male wistar rats were randomly divided into four groups of eight in each group: asthma group (group Ⅰ), asthma+ aspergillus spores (group Ⅱ), asthma+ saline (group Ⅲ), asthma+ aspergillus spores+ TGF-β1 inhibitor (group Ⅳ). The rat model of asthma was induced by ovalbumin (OVA). Group Ⅱ, Ⅲ and Ⅳ of rats inhaled spore suspension of aspergillus fumigatus or saline respectively 100 μl, at d23, d26, d30, d33, d37, d40.Group Ⅳ of rats inhaled Sb-431542 0.5 ml of 14 mg/L, in 1 hour before inhalation of aspergillus fumigatus spores.The content of TGF-β1 in bronchoalveolar lavage fluid (BALF) supernatant solution was determined by enzyme linked immunosorbent assay kit.The lung tissues were stained with TGF-β1 immunohistochemistry, hematoxylin-eosin staining, masson staining. Results In group Ⅱ, the thickness of bronchial wall, the thickness of bronchial smooth muscle, the subepithelial collagen deposition, the content of TGF-β1 in BALF and the expression of TGF-β1 in lung tissue were all higher than those in group Ⅲ (t=7.60, 6.58, 9.14, 7.89, 21.06, all P<0.05). In group Ⅳ, the thickness of the bronchial wall, the thickness of the bronchial smooth muscle, the subepithelial collagen deposition, the TGF-β1 content in BALF and the expression of TGF-β1 in lung tissue were all lower than those in group Ⅱ (t=6.64, 5.06, 6.58, 2.98, 5.90, all P<0.05). Conclusions Exposure to aspergillusus fumigatus can aggravate airway remodeling in asthma rats and up-regulate the expression of TGF-β1.TGF-β1 inhibitor can reduce airway remodeling caused by aspergillusus fumigatus exposure, indicating that TGF-β1 is involved in airway remodeling of asthma rats caused by aspergillusus fumigatus exposure. Key words: Aspergillusus fumigatus; Transforming growth factor beta 1; Asthma; Airway remodeling