目的:探讨Notch信号通路在哮喘上皮下纤维化中的调控作用。方法:首先针对I型胶原蛋白启动子进行生物信息分析,了解有无Notch信号通路结合位点;其次通过DNA-pull down及Western blot实验来证实Notch信号通路下游关键分子Hes1与人和小鼠I型胶原蛋白亚型基因有无结合;最后建立哮喘小鼠模型,用免疫荧光检测哮喘小鼠肺中I型胶原蛋白2个亚型在肺组织中的分布情况,并予Notch信号通路抑制剂Kyo T2腺病毒载体经鼻干预,通过EVG染色观察哮喘气道上皮下纤维化情况。结果:生物信息学分析证实I型胶原蛋白2个亚型的启动子转录位点附近均存在Notch下游关键分子Hes1的结合位点。DNA-pull down及Western blot实验证实Hes1蛋白结合于I型胶原蛋白启动子转录位点附近。哮喘小鼠模型中I型胶原蛋白的2个亚型在肺组织中的表达较正常对照组增多,差异有统计学显著性(P〈0.05)。哮喘小鼠模型经Notch抑制剂干预后肺组织中胶原纤维减少,气道上皮下纤维化得到缓解。结论:Notch能调控哮喘小鼠气道上皮下纤维化这一气道重构现象,抑制Notch信号通路减轻善哮喘小鼠气道上皮下纤维化。
AIM: To investigate the role of Notch signaling in regulating airway subepithelial fibrosis in the asthmatic mice. METHODS: The binding sites of Notch signaling molecules in type I collagen gene promoter were analyzed by bioinformatic methods. DNA-pull down assay and Western blot were further performed to verify Hes1 binding to type I collagen gene. The mouse asthmatic model was established and the type I collagen expression in the lung tissues were detected by immunofluorescence staining. To explore the Notch efficacy on asthmatic airway subepithelial fibrosis,mouse asthmatic model was intranasally administered recombinant adenovirus vectors containing Kyo T2. Then the airway subepithelial fibrosis of asthmatic mouse model was evaluated by EVG staining. RESULTS: The results of bioinformatic analysis showed that Hes1 binding to type I collagen gene near to its transcription site was observed. The results of DNA-pull down assay and Western blot confirmed this binding. The expression of type I collagen in the asthmatic mice was higher than that in the normal mice( P〈0. 05). Furthermore,EVG staining showed more severe airway subepithelial fibrosis in the asthmatic model than that in the control( P〈0. 01). CONCLUSION: Notch signaling has great efficiency in regulating airway subepithelial fibrosis in asthmatic mouse model,and the Notch signaling repressor down-regulates airway subepithelial fibrosis in the asthmatic mice.