黄芪甲苷对哮喘小鼠转化生长因子β1和胸腺基质淋巴细胞生成素表达的影响

目的 观察黄芪甲苷对哮喘模型小鼠呼吸道重塑以及对转化生长因子(TGF)-β1和胸腺基质淋巴细胞生成素(TSLP)表达的影响.方法 48只BALB/c小鼠按随机分成对照组、哮喘组、黄芪甲苷组,布地奈德组,每组12只.卵蛋白致敏、激发8周,黄芪甲苷组给予黄芪甲苷溶液(50 mg/kg)灌胃,1次/d,共8周.检测小鼠呼吸道阻力,肺组织病理检查观察呼吸道炎症、杯状细胞增生、胶原染色面积；酶联免疫吸附( ELISA)法检测支气管肺泡灌洗液(BALF)中自细胞介素(IL)-4和IL-13表达,免疫组化检测α-平滑肌肌动蛋白(α-SMA)表达,实时定量PCR和Western印迹检测TGF-β1和TSLP的表达.结果 小鼠呼吸道阻力结果显示,乙酰胆碱浓度30 μg/kg时,黄芪甲苷和布地奈德能显著抑制哮喘小鼠的呼吸道阻力(均P＜0.05).哮喘组PAS+上皮细胞/支气管上皮细胞、胶原染色面积和α-SMA染色面积明显高于对照组(均P＜0.01),黄芪甲苷组和布地奈德组明显低于哮喘组(均P＜0.05).哮喘组BALF中IL-4和IL-13明显高于对照组(均P＜0.01),黄芪甲苷组和布地奈德组明显低于哮喘组(均P＜0.05).哮喘组TGF-β1和TSLP的mRNA相对表达量(5.23±1.44和5.70±1.65)明显高于对照组(1.02±0.21和1.02±0.25)(均P＜0.01),黄芪甲苷(2.27±0.65和2.97±1.03)和布地奈德组(2.10±0.57和3.32±1.11)明显低于哮喘组(均P＜0.05)；哮喘组TGF-β1和TSLP蛋白水平(0.89±0.11和0.74±0.10)明显高于对照组(0.39±0.04和0.44±0.05)、黄芪甲苷(0.51±0.08和0.59±0.12)和布地奈德组(0.55±0.08和0.60±0.08)(均P＜0.05).结论 黄芪甲苷能够抑制哮喘小鼠模型的呼吸道炎症和呼吸道重塑,其机制可能通过抑制TGF-β1和TSLP的表达而实现.

Effects of astragaloside Ⅳ on the expressions of transforming growth factor-β1 and thymic stromal lymphopoietin in a murine model of asthma

Objective To observe the effects of astragaloside Ⅳ on the airway remodeling and the expressions of transforming growth factor (TGF)-31 and thymic stromal lymphopoietin (TSLP) in a murine model of asthma.Methods Forty-eight BALB/c mice were randomly divided into 4 groups,i.e.control group,asthma group,astragaloside Ⅳ group and budesonide group (n =12 each).The BALB/c mice sensitized to ovalbumin (OVA) were chronically challenged with aerosolized OVA for 8 weeks while the mice in the astragaloside Ⅳ group were intragastrically administered with astragaloside Ⅳ (50 mg/kg) daily for 8 consecutive weeks. Pulmonary functions were measured to evaluate the resistance of expiration. And pulmonary histopathological analysis was performed to observe the infiltration of inflammatory cells,the hyperplasia of airway global cells and the deposition of collagen.The levels of interleukin (IL)-4 and IL-13 in bronchoalveolar lavage fluid (BALF) were measured by ELISA (enzyme linked immunosorbent assay).The pulmonary expression of αt-SMA (alpha-smooth muscle actin) was evaluated by immunohistochemistry.The mRNA and protein expressions of TGF-β1 and TSLP were measured by real-time PCR ( polymerase chain reaction) and Western blot respectively.Results The treatment of astragaloside Ⅳ or budesonide led to a sharp decrease in airway resistance compared with the asthma group at a concentration of acetylcholine in 30 μg/kg ( P ＜0.05 ).The PAS + epithelial/bronchial epithelial cells,the area of collagen staining and α-SMA staining area were significantly elevated in the asthma group compared with the control group ( all P ＜ 0.01 ) while those in the astragaloside and budesonide groups were obviously inhibited compared with the asthma group (all P ＜ 0.05).The BALF levels of IL-4 and IL-13 were markedly elevated in the asthma group versus the control group ( P ＜ 0.01 ) while those markedly decreased in the astragaloside and budesonide groups versus the asthma group ( all P ＜ 0.05 ).The relative expressions of TGF-β1 and TSLP mRNA (5.23 ± 1.44,5.70 ± 1.65 ) were significantly up-regulated in the asthma group versus the control group (1.02±0.21,1.02 ±0.25) (P＜0.01) while those in the astragaloside (2.27 ±0.65,2.97 ± 1.03) and budesonide groups (2.10 ± 0.57,3.32 ± 1.11 ) were obviously down-regulated versus the asthma group (all P＜0.05).The protein levels of TGF-β1 and TSLP in the asthma group (0.89 ±0.11,0.74 ± 0.10) were markedly elevated versus the control (0.39 ± 0.04,0.44 ± 0.05 ),the astragaloside (0.51 ±0.08,0.59±0.12) and the budesonide groups (0.55 ±0.08,0.60 ±0.08) (all P ＜0.05).Conclusion Astragaloside Ⅳ can suppress the progression of airway inflammation, airway hyperresponsiveness and remodeling in a murine model of asthma.The above effects may be partially due to the inhibited expressions of TGF-β1 and TSLP.