大环内酯类抗生素对大鼠气道黏液高分泌模型的干预作用研究

Airway mucus hypersecretion in rats is inhibited by macrolide antibiotics

目的探讨大环内酯类抗生素对丙烯醛诱导的大鼠黏液高分泌模型的干预作用,以及核因子-κB(NF-κB)在黏液高分泌发病机制中的作用。方法30只雄性SD大鼠随机分为5组(n=6):空白对照组(吸入生理盐水)、模型组(吸入丙烯醛)、红霉素组(吸入丙烯醛+红霉素管饲)、克拉霉素组(吸入丙烯醛+克拉霉素管饲)、阿奇霉素组(吸入丙烯醛+阿奇霉素管饲)。大鼠吸入丙烯醛建立气道黏液高分泌模型。采用免疫组化检测肺内气道的Muc5ac和NF-κB的蛋白表达,RT-PCR法检测肺组织Muc5acmRNA;ELISA法检测支气管肺泡灌洗液(BALF)中的肿瘤坏死因子-α(TNF-α)浓度。结果(1)模型组大鼠肺组织中Muc5ACmRNA表达明显高于空白对照组;与模型组比较,红霉素组和克拉霉素组显著降低(P<0.05),阿奇霉素组稍降低。肺内气道上皮Muc5AC水平的改变与Muc5ACmRNA改变相似。(2)模型组NF-κB入核率增加,红霉素和克拉霉素干预后NF-κB入核率明显降低。(3)BALF中TNF-α与Muc5acmRNA的表达呈正相关(r=0.936,P<0.05);NF-κB的入核率与BALF中的TNF-α浓度呈正相关(r=0.911,P<0.05);NF-κB的入核率与黏蛋白Muc5acmRNA的表达呈正相关(r=0.892,P<0.05)。结论红霉素和克拉霉素可抑制丙烯醛诱导的大鼠黏液高分泌状态,其机制可能是通过抑制NF-κB的活化而发挥作用,亦可能与TNF-α被抑制有关。

Objective To investigate the effects of macrolide on and the role of nuclear factor-roB （NF-kB） in airway mucus hypersecretion stimulated by acroleln in rats. Methods Thirty male SD rats were randomly divided into 5 groups （ n = 6 in each group）. Rat airway mucus hypersecretion models were induced by inhaling acrolein and SAM controlled by inhaling saline. The erythromycin, clarithromycin and azithromycin groups were inhaled acrolein and fed with erythromycin, clarithromycin and azithromycin, respectively. MucSac and its mRNA expression were assayed by immunohistochemistry and RT-PCR, and NF-kB was detected by immunohistochemistry. ELISA technique was performed to detect tumor necrosis factor-α （TNF-α） in bronchoalveolar lavage fluid（BALF）. Results Acrolein significantly induced the expressions of MucSac mRNA and protein in bronchial epithelia, and increased the release of TNF-α in BALF. Moreover, acrolein increased the ratio of NF-kB nuclear translocation in airway epithelial cells. The up-regulated expression of Muc.Sac mRNA was positively correlated with NF-tcB activation and level of TNF-α （both P 〈 0.05 ）. Erythromycin and elarithromyein significantly attenuated bronchial MucSac expresson and NF-kB nuclear translocation and reduced the level of TNF-α. Conclusions The activation of NF-kB may be involved in lung inflammation and mucus hypersecretion stimulated by acrolein. The inhibitory effect of erythromycin and clarithromycin may be attributed to the reduction of NF-kB activation and TNF-α released in the lung.