三氧化二砷对哮喘小鼠肺组织IκB-α表达和核因子κB激活的作用

Effect of arsenic trioxide on IκB-alpha expression and nuclear factor κB activation by arsenic trioxide

目的研究三氧化二砷(As2O3)对哮喘小鼠肺组织核因子κB(NF-κB)激活和抑制蛋白IκB-α表达的影响,探讨As2O3抗炎作用的可能机制以及哮喘防治的新思路。方法BALB/c小鼠36只随机分为对照组、哮喘组(卵蛋白末次激发后1,4,12和24h)和As2O3治疗组(4mg/kg),每组6只。Diff-Quick染色观察支气管肺泡灌洗液(bronchoalveolarlavagefluid,BALF)中嗜酸细胞募集特点,电泳迁移率实验和免疫印迹实验分别检测肺组织NF-κB活性和IκB-α表达水平。结果①哮喘组BALF中嗜酸细胞募集[(48.72±5.38)%]较对照组[(0.56±0.21)%]增加(q=33.46,P<0.01),治疗组较哮喘组减少(q=34.65,P<0.01)。②哮喘组肺组织NF-κB活性均较对照组增加(q=41.84,72.75,61.61,16.32,P<0.01或0.05),以4h活性最高,治疗组较哮喘组减少(q=89.48,P<0.01)。③哮喘组肺组织IκB-α表达较对照组减少(q=30.94,P<0.01),治疗组较哮喘组增加(q=23.67,P<0.01)。④BALF中嗜酸细胞募集、肺组织NF-κB活性与IκB-α表达水平均呈负相关(r=-0.82,-0.94,P<0.01)。结论肺组织NF-κB过度激活可能是哮喘慢性气道炎症持续存在的基础;诱导肺组织IκB-α表达和抑制NF-κB激活,可能是As2O3发挥广泛抗炎作用的重要机制。

AIM: To investigate the effect of arsenic trioxide(As2O3) on activation of nuclear factor κB(NF κB) and expression of inhibitor of NF κB alpha(IκB α), and explore the possible mechanism of As2O3 for anti inflammation as well as novel strategy for chronic obstructive pulmonary disease(COPD). METHODS:Thirty six BALB/c mice were randomly divided into control group,asthmatic group(subdivided into 1, 4,12 and 24 hour timepoints after last ovalbumin challenge),and therapeutic group of As2O3(4 mg/kg). There were 6 mice in each group.The characteristic recruitment of eosinophils in bronchoalveolar lavage fluid (BALF) was examined by Diff Quick staining.The pulmonary NF κB activity and IκB αexpression were detected by electrophoretic mobility shift assay(EMSA) and Western blotting, respectively.RESULTS: ①The recruitment of eosinophils in BALF of the asthmatic group[(48.72±5.38)%] was increased than that of the control group[(0.56±0.21)%](q = 33.46,P< 0.01), and it was decreased in the therapeutic group (q = 34.65,P< 0.01).②The pulmonary NF κB activity of the asthmatic group at various timepoints,peaking at 4 hours,was increased than that of the control group(q = 41.84,72.75,61.61 and 16.32,P< 0.01 or 0.05),and it was decreased in the therapeutic group (q = 89.48, P< 0.01).③The pulmonary IκB αexpression of the asthmatic group was decreased than that of the control group (q =30.94,P< 0.01),and it was increased in the therapeutic group (q = 23.67,P< 0.01).④There was a negative correlation between the recruitment of eosinophils in BALF, pulmonary NF κB activity and IκB αexpression(r =-0.82 and-0.94,P< 0.01).CONCLUSION:Increased activation of NF κB may be the basis for perpetuation of chronic airway inflammation in asthma. As2O3 can inhibit pulmonary NF κB activation by induction of IκB αexpression, which may be a vital mechanism for its multiple antiinflammation.