白介素-4在博莱霉素致大鼠肺纤维模型中的表达

The expression of IL-4 in bleomycin-induced pulmonary fibrosis in rats

目的检测IL-4在博莱霉素致大鼠肺纤维化模型中的表达,从而探讨IL-4在肺纤维化发病机制中的作用。方法体重170～190g的雌性wistar大鼠,立即气管内灌注博莱霉素5mg/(kg·bw)建立肺纤维化模型,设立生理盐水对照组。第7、14天分别处死大鼠,收获肺组织及血清,右肺行苏木精-伊红(HE)染色,左肺经逆转录-聚合酶链式反应(RT-PCR)检测肺组织中IL-4mRNA的表达,酶联免疫吸附实验(ELISA)检测血清中IL-4的水平。结果灌注博莱霉素后第7天肺组织病变以肺泡炎为主,第14天肺内有纤维化病灶形成。模型组大鼠IL-4mRNA相对表达强度和IL-4蛋白质水平明显高于对照组,差异有显著性(P<0.05)。结论在肺纤维化大鼠模型中IL-4的产生明显增高,IL-4在肺纤维化发病机制中具有重要作用。可将调节IL-4的产生及拮抗IL-4的作用作为肺纤维化治疗研究的新方向。

Objective:To detect the expression of IL-4 in bleomycin-induced pulmonary fibrosis in rats and to study the effect of IL-4 in pulmonary fibrosis pathogenesis.Methods:Female wistar rats (170～190g weight) were treated with bleomycin(5 mg/kg weight) by intratracheal perfusion on day 0 to induce pulmonary fibrosis,while the controlled animals were only injected with normal saline (NS).The rats were killed on day 7 and 14,and lung tissue and blood serum were collected.The right lung was stained with hematoxylin-eosin.Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of IL-4mRNA in the left lung and ELISA was used to detect the levels of IL-4 in blood serum.Results:Alveolus inflammation was observed on day 7 and fibrosis focus was found on day 14.Compared with controlled group,the expression levels of IL-4mRNA in lung tissue and the levels of IL-4 in blood serum were elevated significantly in model groups(P<0.05).Conclusion:IL-4 may play an important role in pathogenesis of pulmonary fibrosis,and possibly,the down-regulation of IL-4 level or antagonist of IL-4 could be taken as a new direction for studying the treatment of pulmonary fibrosis.