哮喘大鼠肺内神经生长因子表达与气道炎症的相关性

Expression of Nerve Growth Factor in Relation to the Airway Inflammation in Rat Lung

目的:探讨哮喘大鼠肺内神经生长因子(NGF)与气道炎症相关指标的关系,为抗NGF治疗哮喘提供实验数据。方法:48只SD大鼠随机等分为:对照组、哮喘组和NGF阻断组。光镜下测量支气管基底膜厚度及计数黏膜下成纤维细胞的数目。HE染色观察气道病理改变,碱水解法检测肺组织中羟脯氨酸的含量并以此计算胶原蛋白的含量,ELISA法检测肺组织中纤维连接蛋白(FN)和免疫组化方法结合显微图像分析检测NGF含量;RT-PCR检测支气管NGF mRNA的表达。结果:①哮喘组支气管基底膜增厚,黏膜下成纤维细胞数目增多、胶原蛋白、FN含量增加,与NGF阻断组和对照组比较差异有统计学意义(P<0.05);②哮喘组支气管NGF mRNA及蛋白表达增加,与NGF阻断组和对照组比较,差异均有统计学意义(P<0.05);③哮喘组支气管NGF含量与基底膜厚度、黏膜下成纤维细胞数目、胶原蛋白、FN含量、气道壁厚度成正相关。结论:哮喘大鼠支气管NGF mRNA表达水平显著增加,并与气道炎症指标呈正相关,予NGF阻断后气道炎症明显减轻。

Objective：To investigate the relationship between nerve growth factor（NGF） expression and airway inflammation indicators in the asthmatic rats.Methods：Forty-eight SD rats were randomly divided into three groups：control group,asthma group,and the NGF blocking group.The bronchial submucosal basement membrane thickness and the number of fibroblasts were determined by light microscope.HE staining of airway tissues was performed before measuring the airway wall thickness.Alkaline hydrolysis was adopted to determine the content of hydroxyproline in the lung tissue in order to calculate the collagen content.Expression of fibronectin in lung tissue was assayed by ELISA,and NGF expression was determined by immunohistochemical staining.RT-PCR was adopted to detect the level of bronchial NGF-mRNA.Results：①Basement membrane thickness,the number of submucosal fibroblasts,collagen and FN contents were increased in athma group as compared with those in NGF blocking group and control group（P0.05）;②The bronchial NGF mRNA and protein levels in asthma group were higher than in NGF blocking group and control group（P0.05）;③The basement membrane thickness,the number of submucosal fibroblasts,collagen and FN contents,and airway wall thickness were positively correlated with the NGF expression levels in lungs of asthma group.Conclusion：The expression of bronchial NGF in asthmatic rats is significantly increased,which is positively correlated with airway inflammation.The intervention of anti-NGF could inhibit airway inflammation.