硫化氢对急性肺损伤大鼠肺组织核转录因子κB及细胞间黏附分子1表达的影响

Effects of hydrogen sulfide on the expressions of nuclear factor-KB and intercellular adhesion molecule 1 in pulmonary tissue of rats with acute lung injury

目的探讨硫化氢（H：S）对油酸诱导的急性肺损伤（ALI）大鼠肺组织核转录因子κB（NF—κB）与细胞间黏附分子1（ICAM-1）表达的影响。方法雄性sD大鼠42只，采用随机数方法分为对照组（6只）、油酸组及油酸＋硫氢化钠（NariS）组，后2组大鼠分别在2、4、6h3个时间点进行观察，每个时间点大鼠为6只。复制大鼠Au模型，对照组大鼠经过尾静脉注射0．1mL／kg生理盐水；油酸组大鼠通过尾静脉注射油酸0．1ml/kg；油酸＋NariS组大鼠先腹腔注射NariS56μmol／kg（溶于0．5m1生理盐水），30min后经大鼠尾静脉注射油酸0．1ml／kg。对支气管肺泡灌洗液沉渣行瑞士染色进行白细胞分类计数；对大鼠肺组织病变进行半定量肺损伤评分；测定肺组织中H2s的含量；应用免疫组织化学法对肺泡上皮细胞中ICAM-1表达进行定位及半定量分析，并对NF—KB核转位进行半定量分析。结果油酸组大鼠2、4、6h支气管肺泡灌洗液多形核白细胞（PMN）比例[（74．5±3．0）％、（80．2±2．0）％和（87．2±2．7）％]及肺损伤评分（5．2±0．8、6．d±0．6和6．8±0．8）均明显高于对照组[（3．1±1．6）％和0．4±0．6，均P〈0．01]；肺组织中H2S含量均明显低于对照组（21．20±0．38）μmoL／g、（20．80±0．53）μmol／g、（18．92±0．75）μmol／g比（26．81±0．65）μmoL／g，均P〈0．01]；肺泡上皮细胞中NF-κB核表达和ICAM-1胞膜表达则均明显高于对照组（均P〈0．05）。油酸＋NaHS组支气管肺泡灌洗液PMN比例及肺损伤评分在2、4和6h3个时间点均明显低于油酸组（均P〈0．05）；肺组织中H2s含量在4和6h明显高于油酸组（均P〈0．05）；肺泡上皮细胞中NF—κB核表达和ICAM-1胞膜表达在4和6h则明显低于油酸组相应时间点（均P〈0．05）。结论H2s可能通过抑制ALI大鼠肺部炎症反应发挥保护效应，其抗炎效应与其抑制大鼠肺泡上皮细胞NF—κB的表达有关。

Objective To explore the potential effects of hydrogen sulfide （H2 S） on nuclear factor kappa B （NF-KB） and intercellular adhesion molecule 1 （ICAM-1） in lung tissue with oleic acid （OA）- induced acute lung injury （ALI） in rats. Methods Forty-two rats were randomly divided into 3 groups ： control （n = 6）, OA （n = 18） and OA ＋ Naris （n = 18 ）. Rats in the OA group received an intra-tail vein injection of oleic acid 0. 1 ml/kg while those in the OA ＋ Naris group an iutraperitoneal injection of Naris 56 μmol/kg at 30 mins before OA injection. The OA and OA ＋ Naris groups were subdivided into 3 subgroups depending on the therapeutic duration：2 h （n =6）, 4 h （n =6） and 6 h （n =6）. Rats in the control group received an intra-tail vein injection of normal saline 0. 1 ml/kg. Bronehioalveolar lavage fluid （BALF） was collected and the leucocytic differential count of sediment examined. The extent of lung injury was evaluated by the index of quantitative assessment （IQA）. The H2 S level in lung tissue was measured by sensitive sulphur electrode. The nuclear translocation of NF-KB and the expression of ICAM-1 in alveolar epithelial cells were measured by immunohistochemical staining. Results Compared with the control group, the BALF percentage of polymorphonuclear （PMN） cell was significantly higher at 2, 4 and 6 h in the OA-treated rats [（74.5±3.0）%, （80.2±2.0）%, （87.2±2.7）% vs （3.1±1.6）%, all P 〈 0. 01]. And the value of IQA increased significantly versus those at 2, 4 and 6 h in the control group （5.2±0. 8, 6.4±0.6, 6.8 ＋0. 8 vs 0.4±0.6, all P 〈0. 01）. And the levels of H2S in lung tissue decreased at 2,4 and 6 h [（21.20±0.38）μmol/g, （20.80±0.53）μmol/g, （18.92±0.75） μmol/g vs （26.81±0.65） μmol/g, all P 〈 0. 01 ]. Moreover, the nuclear expression of NF-κB and the membranous expression of ICAM-lin the alveolar epithelial cells in OA group rats was significantly higher than those of the control group （ all P 〈 0. 05 ）. After the dosing of H2S donor （ NariS）, the BALF percentage of PMN cell and the lung IQA decreased in the three subgroup rats （2, 4 and 6 h） versus the OA group. And the concentration of HzS increased significantly in the 4 h and 6 h subgroups versus the OA group at the corresponding time points. Simultaneously, the nuclear expression of NF-κB and the membranous expression of ICAM-1 in alveolar epithelial cells were significantly lower than that of the OA group at 4 h and 6 h subgroups （ all P 〈 0. 05）. Conclusion H2S may play a protective role in the ALI rats through the suppression of lung inflammation. And the inhibited expression of alveolar epithelial cell NF-κB mediates the anti-inflammatory effects of H2 S.