百草枯致大鼠肺纤维化肺组织内质网相关凋亡基因Caspase-12的表达

目的 观察内质网相关凋亡基因半胱氨酸天冬氨酸蛋白酶12（ Caspase-12） 在百草枯诱导肺纤维化模型大鼠肺组织中的表达。方法 30 只Spragne-Dawley（ SD） 大鼠随机分为对照组、14 d模型组和28 d 模型组。采用百草枯灌胃法复制肺纤维化模型。逆转录-聚合酶链反应（ RT-PCR）检测肺内Caspase-12 mRNA 表达, 免疫组化检测其蛋白表达。HE 和Masson 染色判断肺组织肺泡炎及肺纤维化程度。结果 HE 和Masson 染色结果证实成功复制肺纤维化模型。模型组大鼠肺泡炎和肺纤维化程度较对照组严重（ P 〈0. 01） 。与对照组比较, Caspase-12 表达在14 d 模型组中明显升高（ P 〈0. 01） , 在28 d 模型组中更高（ P 〈 0. 01） 。结论 百草枯中毒大鼠肺内质网相关凋亡基因Caspase-12 表达增高, 提示内质网应激在百草枯中毒引起的肺纤维化中发挥重要作用。

Expression of Endoplasmic Reticulum Stress Associated Apoptosis Gene Caspase-12 in Lung ofParaquat-induced Pulmonary Fibrosis Rats

Objective To investigate the endoplasmic reticulum stress associated apoptosis geneCaspase-12 expression in paraquat-induced pulmonary fibrosis.Methods 30 adult healthy Sprague-Dawley（ SD） rats were randomly divided into a nomal control group, two pulmonary fibrosis model groups（ intragastrically administered paraquat for 14 days and 28 days, respectively） . The model of pulmonaryfibrosis was established through intragastrically administering paraquat at the dose of 30 mg/kg. RT-PCR wasused to determine the mRNA expression of Caspase-12. Immunohistochemistry was used to determine theprotein expression of Caspase-12. HE staining and Masson staining were used to determine the degree ofalveolitis and pulmonary fibrosis.Results HE staining and Masson staining of lung tissues proved thatpulmonary fibrosis model was successfully constructed. The degree of alveolitis and pulmonary fibrosis in themodel group was significantly more serious than that in the control group （ P 〈 0. 01） . RT-PCR andImmunohistochemistry results showed that the expression of Caspase-12 were remarkably increased in thepulmonary fibrosis model group（ 14 d group） （ P 〈0. 01） , even more elevated in 28 d group compared withthe 14 d group.Conclusion The results demonstrate that the expression of Caspase-12 in paraquat poisonedrats is up-regulated, suggesting endoplasmic reticulum stress plays an important role in paraquat inducedpulmonaryfibrosis.