穴位贴敷对慢性哮喘小鼠气道重塑及转化生长因子β1/Smad 3表达的影响

Inhibitory Effect of Acupoint Application on Airway Remodeling and Expression of TGF-β1/Smad 3 in the Lung Tissue of Chronic Asthma Mice

目的:探讨转化生长因子β1(TGF-β1)/Smad 3信号通路在穴位贴敷改善慢性哮喘小鼠气道重塑中的作用机制。方法:BALB/c小鼠随机分为正常组、模型组、假穴位贴敷组、穴位贴敷组、地塞米松组,每组8只,采用卵白蛋白致敏的方法制备慢性哮喘模型。穴位贴敷组运用白芥子、延胡索、生甘遂、细辛组方药贴贴敷双侧"肺俞""心俞""膈俞",假穴位贴敷组运用凡士林药贴贴敷双侧"肺俞""心俞""膈俞",两组均每次贴敷6h,每日1次,共治疗14d;地塞米松组腹腔注射地塞米松1mg/kg,每日1次,共治疗14d。应用小鼠肺功能仪检测气道阻力,应用苏木精-伊红染色在光镜下观察各组小鼠气道病理学改变,应用图像分析软件测定肺内支气管管壁面积(WAt)/管腔内周长(Pi)、管壁平滑肌面积(WAm)/Pi,应用免疫组化法检测小鼠肺组织中TGF-β1及Smad 3蛋白表达。结果:与正常组相比,模型组和假穴位贴敷组小鼠气道阻力、WAt/Pi、WAm/Pi、肺组织TGF-β1和Smad 3蛋白表达均显著增高(P<0.01);穴位贴敷组、地塞米松组与模型组、假穴位贴敷组比较,小鼠气道阻力、WAt/Pi、WAm/Pi、肺组织中TGF-β1及Smad 3蛋白表达均下降(P<0.05);穴位贴敷组和地塞米松组之间比较,各指标差异均无统计学意义(P>0.05)。模型组支气管管壁大量炎性细胞浸润,管腔狭窄,气道上皮增生,支气管黏膜水肿增厚;穴位贴敷组肺泡内少量炎性细胞浸润,肺间隔未见明显增厚;地塞米松组小气道黏膜上皮较完整,肺间隔未见明显增厚。结论:穴位贴敷可通过下调慢性哮喘小鼠气道TGF-β1/Smad 3通路以改善气道重塑,从而治疗慢性哮喘。

Objective To observe the effect of acupoint application on transforming growth factor （TGF）-β 1/Smad 3 signaling pathway, so as to reveal its mechanism underlying improvement of airway remodeling in chronic asthma mice. Methods BALB/c mice were randomly divided into normal group,model group, sham acupoint application group （sham group）,acupoint application group, and dexamethasone group （n = 8 in each group）. The chronic asthma model was established by intraperitoneal injection of ovalbumin sensitization. The acupoint application group was treated with plaster composed with White Mustard Seed, Rhizoma Corydalis, Unprocessed Radix Kansui, and Herba Asari, on bilateral ＂Feishu＂ （BL 13）, ＂Xinshu＂ （BL 15） and ＂Geshu＂ （BL 17） points, 6 hours a day for 14 days. The sham group was treated with piaster containing vaseline on bilateral BL 13, BL 15 and BL 17, 6 hours a day for 14 days. The dexamethasone group was treated with dexamethasone 1 mg· kg-1· day-1 intraperi- toneally, once daily for 14 days. At the end of treatment, airway resistance was detected by mouse lung function instrument. Patho-logical changes of airway were observed under light microscope after hematoxylin-eosin staining, and the morphological pa- rameters were measured by image analysis software. Immunohistochemistry method was used to detect the expression of TGF-β 1 and Smad 3 in the lung tissue of mice. Results Compared with the normal group, the airway resistance, the total bronchial wall area（WAt）/lumen perimeter （Pi）, the smooth muscle wall area （WAm）/Pi, and the expression of TGF-β 1 and Smad 3 in the lung tis- sues were significantly higher in the model and sham groups （ P〈0.01）. Compared with the model group and the sham group, the airway resistance, WAt/Pi, WAm/Pi, the expression of TGF-β 1 and Smad 3 in the lung tissues were decreased in the acupoint application group and the dexamethasone group （P〈0.05）. There were no significant differences between the acupoint applica- tion group and the dexamethasone group in the above mentioned indexes （P〉0.05）. Conclusion Acupoint application can im- prove airway remodeling by down-regulating the expression of TGF-β 1/Smad 3 in the airway of chronic asthmatic mice.