MKK34多肽对HDM哮喘小鼠气道β-catenin表达及分布的影响

摘要

Objective To explore the role of MKK34 (a peptide spanning a C-terminal α-helical region in TSLP) on airway inflammation and β-catenin of airway epithelium in a HDM-induced mouse asthma.Methods 32 male BALB/c mice were randomly divided into control,MKK34,asthma and MKK34 + HDM groups.The mice in the asthma group were exposed to HDM for five consecutive days and the MKK34 + HDM group was pretreated with MKK34 1 h prior to the HDM intranasally treated.After 8 weeks' treatment,animal lung function test and pathological staining were performed to evaluate the asthma situation,IL-4,IFN-γin bronchoalveolar lavage fluid and IgE in the serum were detected,immunohistochemistry and western blot were used to assess β-catenin and p-ERK,t-ERK levels.Results Airway reactivity,IL-4 and IgE in the asthma group were significantly higher than that in the control group.Treatment with MKK34 significantly decreased airway hyperresponsiveness,IL-4 and IgE.HE staining demonstrated the chronic bronchitic inflammation in the lungs of asthma group.β-catenin in the control group was distributed evenly at the cytomembrane of epithelial cells.In the asthma group,β-catenin was disordered in epithelial cells and its expression was decreased.Treatment with MKK34 ameliorated the damage of β-catenin and chronic bronchitic inflammation.The protein levels of p-ERK1/2 increased obviously in the asthma group.The pretreated group significantly decreased the expression of p-ERK1/2.Conclusions MKK34 can ameliorate the airway inflammation and the destruction of β-catenin of airway epithelium in a HDM-induced mouse asthma.The ERK pathway may play a role in this process.%目的:观察MKK34多肽(TSLP碳端α螺旋区域)对屋尘螨(HDM)哮喘小鼠气道炎症及气道上皮细胞连接蛋白β-catenin的影响.方法:将32只BALB/c小鼠随机分为4组.哮喘组每周连续5d滴鼻给予HDM,预处理组在给予HDM前1h滴鼻给予MKK34多肽,8周后,动物肺功能测定和病理染色来评估哮喘的情况,检测各组小鼠的肺泡灌洗液IL-4、IFN-γ及血清IgE,用免疫组化及Western blot测定肺组织3-catenin的分布和表达及p-ERK1/2、t-ERK1/2的表达.结果:HDM哮喘组气道反应性、肺泡灌洗液IL-4和血清IgE均较对照组增高,MKK34预处理组较哮喘组上述指标都有所改善.肺组织HE染色示哮喘组具有气道炎症的典型病变,而MKK34预处理组炎症明显轻于哮喘组,免疫组化及Western blot结果示,对照组在气道上皮细胞的细胞膜连接处紧密的分布着β-catenin蛋白,而哮喘组β-catenin分布混乱、减少,MKK34预处理组能减少3-catenin的破坏,在哮喘组p-ERK1/2表达明显增加,MKK34多肽预处理组较哮喘组减少.结论:MKK34多肽可能通过抑制ERK的磷酸化来改善HDM哮喘小鼠的气道炎症及气道上皮细胞连接蛋白β-catenin的破坏.