摘要目的 探讨香烟烟雾对哮喘小鼠缺氧诱导因子-1α(HIF-1 α)及组蛋白去乙酰化酶(HDAC2)表达的影响.方法 SPF级雌性BALB/c小鼠30只,按随机数字表法随机平均分为对照组、哮喘组、吸烟哮喘组3组.用卵白蛋白(OVA)致敏和激发的方法制备哮喘和吸烟哮喘模型,其中吸烟哮喘组在激发后置于自制熏箱内被动吸烟,对照组则用生理盐水代替OVA.观察各组小鼠肺组织病理学变化,分析支气管肺泡灌洗液(BALF)中的细胞分类计数,酶联免疫吸附(ELISA)法测定BALF中白细胞介素(IL)-8水平,并采用免疫组织化学法和Western印迹法测定各组小鼠肺组织中HIF-1α及HDAC2表达情况,并作相关性分析.结果 哮喘组和吸烟哮喘组嗜酸粒细胞计数比例均显著高于对照组[(8.90±1.60)％、(7.52±0.63)％比(0.60±0.10)％,均P＜0.01],吸烟哮喘组中性粒细胞计数比例显著高于哮喘组[(18.24±5.19)％比(8.46±1.58)％,P＜0.01];哮喘组和吸烟哮喘组肺组织HIF-1α表达均显著高于对照组(0.144±0.008、0.238±0.015比0.081±0.005)且吸烟哮喘组显著高于哮喘组(均P＜0.01);哮喘组和吸烟哮喘组肺组织HDAC2表达均显著低于对照组(0.287±0.008、0.164 ±0.015比0.452 ±0.041)且吸烟哮喘组显著低于哮喘组(均P＜0.01).吸烟哮喘组BALF中IL-8水平显著高于哮喘组、对照组[(42.07±4.54)比(21.66±2.78)、(14.33±3.73) pg/ml,均P＜0.01],吸烟哮喘组肺组织中HIF-1α与HDAC2的表达呈显著负相关(r=-0.950,P＜0.01),吸烟哮喘组BALF中IL-8的表达与HDAC2的表达呈显著负相关(r=-0.855,P＜0.01).结论 香烟烟雾可能通过激活HIF-1α而抑制HDAC2,加重气道炎症.

abstractsObjective To explore the effects of smoking on airway inflammation through the expressions of hypoxia-inducible factor-1α (HIF-1α) and histone deacetylase-2 (HDAC2) in asthmatic mice.Methods A total of 30 female SPF BALB/c mice were divided randomly into 3 groups of control (C),asthma (A) and smoking asthma (S).The latter two groups were sensitized and challenged with ovalbumin (OVA) for asthmatic modeling.The mice of group S were placed into a self-made fumigating box for passive smoking.While group S was sensitized and challenged with normal saline instead of OVA.The pathological changes of different groups were observed.The different cell counts of bronchoalveolar fluid (BALF) were analyzed.The expressions of HIF-1α and HDAC2 were detected by immunohistochemistry.The level of interleukin (IL)-8 in BALF was detected by enzyme-linked immunosorbent assay (ELISA).And the levels of HIF-1 α and HDAC2 in lung homogenate were measured by Western blot.Results The ratios of eosinophil (EOS) to total cell numbers of BALF in groups A and S were significantly higher than that in group C ((8.90 ± 1.60) ％,(7.52 ± 0.63) ％ vs (0.60 ± 0.10) ％,both P ＜ 0.01),while the ratio of neutrophile (NEU) in group S was higher than that in group A ((18.24 ±5.19)％ vs (8.46 ± 1.58)％,P ＜0.01).Western blot showed that HIF-1α expressions in lung homogenate of groups A and S were significantly elevated than that in groups C (0.144 ± 0.008,0.238 ± 0.015 vs 0.081 ± 0.005,both P ＜0.01).While the HIF-1α level of group S was higher than that of group A (P ＜ 0.01).And the expressions of HDAC2 in groups A and S significantly decreased than that in group C (0.287 ± 0.008,0.164 ±0.015 vs 0.452 ±0.041,both P ＜0.01).While the HDAC2 level of group S was lower than that of group A (P ＜ 0.01).The BALF level of IL-8 in group S was higher than those in groups A and C ((42.07 ± 4.54) vs (21.66 ± 2.78),(14.33 ± 3.73) pg/ml,both P ＜ 0.01).There were significantly negative correlations between the expressions of HIF-1 α and HDAC2 (r =-0.950,P ＜ 0.01) in lung as well as HDAC2 in lung and IL-8 (r =-0.855,P ＜ 0.01) in BALF.Conclusion Cigarette smoking aggravates the airway inflammation through a down-regulated expression of HDAC2 by activating HIF-1 α.