Nrf2在支气管哮喘豚鼠炎症细胞中调控γ-谷氨酰半胱氨酸合成酶的表达

目的：探讨核因子相关因子-2(Nrf2)调控γ-谷氨酰半胱氨酸合成酶(γ-GCS)在支气管哮喘豚鼠肺泡灌洗液(BALF)炎症细胞中的表达。方法：38只健康雄性豚鼠随机分为对照组（A组）、哮喘组（B组）和地塞米松治疗组（C组），卵蛋白致敏法复制哮喘模型，检测3组豚鼠肺组织匀浆中丙二醛（MDA）浓度，收集BALF，行细胞计数和分类。离心，细胞涂片行免疫细胞化学和原位杂交，检测Nrf2、Bach1、γ-GCS蛋白和mRNA。结果：（1）B组嗜酸性粒细胞数（EOS）比例高于A组和C组；（2）肺组织中MDA浓度B组高于A组和C组；（3）γ-GCS原位杂交A组A值高于B组和C组；Nrf2、Bach1原位杂交A值3组差异无显著；（4）γ-GCS 免疫细胞化学B组A值低于A组；Nrf2细胞核内阳性率 B组低于A组和C组；Bach1细胞核内阳性率B组高于A组和C组；（5）γ-GCS mRNA表达（A值）与Nrf2核内阳性率呈正相关，与Bach1核内阳性率呈负相关；B组BALF 中γ-GCS mRNA表达（A值）与EOS比例呈负相关。结论：支气管哮喘豚鼠体内存在氧化/抗氧化失衡，炎症反应使γ-GCS在豚鼠支气管哮喘炎症细胞中的表达降低，地塞米松可以通过调节Nrf2/Bach1核转位而增加γ-GCS表达。

Nrf2 regulates the expression of γ-glutamylcysteine synthetase in the inflammatory cells of bronchial asthma guinea pig

AIM:To investigate Nrf2 that regulates the expression of γ-glutamylcysteine synthetase (γ-GCS) in the inflammatory cells in bronchial asthma guinea pig bronchoalveolar lavage fluid (BALF). METHODS:Adult male guinea pigs were randomly divided into control group (group A), asthmatic group (group B) and dexamethasone group (group C). Asthmatic model was established by the method of ovalbumin challenge. MDA concentration in the lung tissue homogenate was detected. The total cell count and the proportion of inflammatory cells in BALF were measured. The methods of immunohistochemistry and in situ hybridization were used for detection of the protein and mRNA expressions of Nrf2, Bach1 and γ-GCS. RESULTS:(1) The proportion of eosinophils (EOS) in BALF and the MDA concentration of the lung tissue in group B were higher than those in group A and group C. (2) The result of in situ hybridization indicated that the A value of γ-GCS was the highest in group A compared to group B and group C, but the A value of Nrf2 and Bach1 in 3 groups has no statistical significance. (3) Immunohistochemistry indicated that the A value of γ-GCS in group B was lower than that in group A. The positive rate in cell nucleus of Nrf2 in group B was lower than that in group A and group C. The positive rate in cell nucleus of Bach1 in group B was higher than that in group A and group C. (4) The mRNA expression of γ-GCS (A value) showed positive correlation with the positive rate in cell nucleus of Nrf2 and negative correlation with the positive rate in cell nucleus. A negative correlation between the proportion of EOS in BALF of group B and the γ-GCS mRNA was observed. CONCLUSION:There is disequilibrium between oxidation and anti-oxidation in bronchial asthma guinea pig. Inflammatory reaction decreases the expression of γ-GCS in the inflammatory cells in bronchial asthma guinea pig. Dexamethasone regulates the nuclear translocation of Nrf2/Bach1 and increases the expression of γ-GCS.