Hes-1与哮喘大鼠气道炎症和气道重塑的关系研究

Relationship between Hes-1 and airway inflammation and remodeling in a rat model of asthma

摘要:

目的 观察Sprague-Dawley（SD）大鼠哮喘模型中Notch 信号通路靶基因Hes-1 的表达变化及与气道炎症和气道重塑的关系，初步探讨其在支气管哮喘发病中的作用。方法 将48 只SD 大鼠随机分成对照组和哮喘组，采用卵白蛋白致敏及激发建立哮喘模型，对照组以生理盐水替代致敏液，两组依据激发后不同处理时间点各分为4 周、8 周、12 周3 个亚组，每组8 只大鼠。光镜观察肺组织病理变化并检测支气管平滑肌厚度（Wam）；ELISA 法检测大鼠血清和支气管肺泡灌洗液（BALF）中IL-4 和INF-γ 水平；分别采用免疫组织化学和实时荧光定量PCR 检测Hes-1 蛋白及mRNA 的表达水平。结果 随着激发后时间的延长，哮喘组大鼠Wam 逐渐增加，血清和BALF 中INF-γ 水平逐渐降低、IL-4 水平逐渐增加，且与同时间点对照组相比差异均有统计学意义（均P<0.05）。哮喘大鼠Hes-1 蛋白及mRNA 的水平随着激发时间延长而逐步增高，且均高于同时间点对照组（均P<0.05）。哮喘组Hes-1 蛋白及其mRNA 的表达与Wam 呈正相关，与血清及BALF 中IL-4 的浓度亦呈正相关，而与血清及BALF 中INF-γ 的浓度呈负相关（均P<0.05）。结论 Hes-1 蛋白及其mRNA 的表达增加与哮喘大鼠气道炎症因子水平和气道平滑肌重塑密切相关，并可能参与了哮喘的发生。

Abstract:

Objective To study the changes of Hes-1, the target gene of Notch signaling pathway, and its relationship with airway inflammation and remodeling in a rat model of asthma. Methods Forty-eight rats were randomly divided into an asthma group and a control group. The rats in the asthma group were sensitized and challenged by ovalbumin (OVA), and normal saline was used in the control group. Two groups were further divided into 3 subgroups according to time points after challenging, i.e. 4 weeks, 8 weeks and 12 weeks (n=8 rats each). Pathological changes of lungs were observed by light microscopy and the thickness of bronchial smooth muscle layer (Wam) was measured. The levels of IL-4 and INF-γ in rat serum and bronchoalveolar lavage fluids (BALF) were measured using ELISA. Expression levels of Hes-1 protein and mRNA were determined by immunohistochemistry and quantitative real-time PCR respectively. Results Together with the extension of challenging, the Wam of rats in the asthma group increased, a decrease of INF-γ level and an increase of IL-4 level in serum and BALF were also observed, and the differences were statistically significant compared with those in the corresponding control group (P<0.05). Hes-1 protein and mRNA levels also increased gradually after OVA challenging and were higher than those in the control group (P<0.05). The levels of Hes-1 protein and mRNA were positively correlated with Wam and IL-4 in serum and BALF, but were inversely correlated with INF-γ in serum and BALF (P<0.05). Conclusions Levels of Hes-1 protein and mRNA increased, which were closely related with the levels of airway inflammatory factors and remodeling of airway smooth muscle. Hes-1 may play an important role in the pathogenesis of asthma.