热休克因子1对过敏性哮喘小鼠气道高反应性和气道炎症的影响

Effect of heat shock factor 1 on airway hyperresponsiveness and airway inflammation in mice with allergic asthma

目的研究热休克因子1(HSF1)对哮喘小鼠气道高反应性和气道炎症的作用及可能机制。方法 36只小鼠随机分为对照组、哮喘组、HSF1小干扰RNA阴性对照组(siHSF1-NC)和siHSF1组,每组9只。采用卵清蛋白(OVA)致敏和激发建立哮喘模型,siHSF1-NC组和siHSF1组小鼠于激发前分别气管内给予siHSF1-NC和siHSF1。末次激发24 h后采用肺功能仪测定气道反应性;直接计数法计算嗜酸性粒细胞(EOS)的数目;ELISA法检测血清OVA特异性Ig E的含量及肺组织和支气管肺泡灌洗液(BALF)中IL-4、IL-5、IL-13和IFN-γ的表达水平;实时荧光定量PCR检测HSF1 mRNA的表达水平;Western blot法检测HSF1、高迁移率蛋白族1(HMGB1)和磷酸化c-jun氨基末端激酶(p-JNK)的蛋白表达水平。结果与对照组相比,哮喘组HSF1 mRNA和蛋白表达升高(P<0.05);与siHSF1-NC组相比,siHSF1组HSF1 mRNA和蛋白表达降低(P<0.05),且HSF1缺失导致气道壁增厚、气道高反应性增强、OVA特异性Ig E含量和EOS的数目增加(P<0.05)。与siHSF1-NC组相比,siHSF1组小鼠BALF和肺组织中IL-4、IL-5和IL-13水平升高,IFN-γ表达减少(P<0.05);HMGB1和p-JNK表达升高(P<0.05)。结论 HSF1缺失加重哮喘小鼠的气道高反应性和气道炎症,其机制可能是通过负调控HMGB1和JNK来实现。

Objective To investigate the effect of heat shock factor 1（HSF1） on airway hyperresponsiveness and airway inflammation in mice with asthma and possible mechanisms. Methods A total of 36 mice were randomly divided into four groups： control, asthma, HSF1 small interfering RNA negative control（siHSF1-NC）, and siHSF1 intervention（n=9 each）. Ovalbumin（OVA） sensitization and challenge were performed to induce asthma in the latter three groups. The mice in the siHSF1-NC and siHSF1 groups were treated with siHSF1-NC and siHSF1, respectively. A spirometer was used to measure airway responsiveness at 24 hours after the last challenge. The direct count method was used to calculate the number of eosinophils. ELISA was used to measure the serum level of OVA-specific Ig E and levels of interleukin-4（IL-4）, interleukin-5（IL-5）, interleukin-13（IL-13）, and interferon-γ（IFN-γ） in lung tissues and bronchoalveolar lavage fluid（BALF）. Quantitative real-time PCR was used to measure the mRNA expression of HSF1 in asthmatic mice. Western blot was used to measure the protein expression of HSF1, high-mobility group box 1（HMGB1）, and phosphorylated c-Jun N-terminal kinase（p-JNK）. Results The asthma group had significant increases in the mRNA and protein expression of HSF1 compared with the control group（P〈0.05）. The siHSF1 group had significantly reduced mRNA and protein expression of HSF1 compared with the siHSF1-NC group（P〈0.05）. The knockdown of HSF1 increased airway wall thickness, airway hyperresponsiveness, OVA-specific Ig E content, and the number of eosinophils（P〈0.05）. Compared with the siHSF1-NC group, the siHSF1 group had significantly increased levels of IL-4, IL-5, and IL-13 and significantly reduced expression of IFN-γ in lung tissues and BALF（P〈0.05）, as well as significantly increased expression of HMGB1 and p-JNK（P〈0.05）. Conclusions Knockdown of HSF1 aggravates airway hyperresponsiveness and airway inflammation in asthmatic mice, and its possible mechanism may involve the negative regulation of HMGB1 and JNK.