摘要
目的:分析颗粒酶B在博来霉素导致大鼠肺纤维化中的作用。方法:将21只SD大鼠随机分为三组：对照组、模型组、干预组，每组7只。模型组和干预组采用经气管内注入博来霉素(5 mg/kg)诱导大鼠肺纤维化动物模型。干预组在造模前1 h、造模第7天、第14天和第21天经尾静脉注射颗粒酶B抑制剂，其它两组经尾静脉注射等体积生理盐水，其余操作相同。28 d后处死大鼠取出肺脏，采用免疫荧光和Western blot检测颗粒酶B、胶原蛋白I、转化生长因子β1(transforming growth factor β1)和Smad3蛋白表达情况，采用Masson染色检测肺组织纤维化情况。结果:模型组较对照组大鼠肺组织胶原蛋白Ⅰ表达上调，胶原蛋白沉积增加，肺纤维化加重。干预组较模型组胶原蛋白Ⅰ表达下调，胶原蛋白沉积减少，肺纤维化减轻。模型组较对照组大鼠肺组织TGF-β1和Smad3蛋白表达增加，干预组较模型组TGF-β1和Smad3蛋白表达降低。结论:颗粒酶B促进了博来霉素导致的大鼠肺纤维化，机制可能与激活TGF-β1/Smad3信号通路有关。
Abstract
Objective:To explore the role of granzyme B in bleomycin-induced pulmonary fibrosis in rats.Methods:21 SD rats were randomly divided into three groups: control group, model group and intervention group, with 7 rats in each group. The model group and the intervention group were injected with bleomycin (5 mg/kg) through the trachea to induce pulmonary fibrosis. The intervention group was injected with granzyme B inhibitor through caudal vein 1 hour before modeling, on day 7, 14 and 21, and the other two groups were injected with equal volume of normal saline. The remaining operations were the same. After 28 days, the rats were killed and the lungs were removed. The protein expressions of granzyme B, collagen I, TGF-β1 and Smad3 were detected by immunofluorescence and Western blot, and the pulmonary fibrosis was detected by Masson staining.Results:Compared with the control group, collagen I expression, collagen deposition and pulmonary fibrosis were up-regulated in the model group. Compared with model group, collagen I expression was down-regulated, collagen deposition was reduced and pulmonary fibrosis was alleviated in the intervention group. The protein expressions of TGF-β1 and Smad3 in lung tissue of model group were increased compared with that of control group, while the protein expressions of TGF-β1 and Smad3 in intervention group were decreased compared with that of model group.Conclusion:Granzyme B can promote bleomycin-induced pulmonary fibrosis in rats, and the mechanism may be related to the activation of TGF-β1/Smad3 signaling pathway.
基金项目
陕西省重点研发计划(2018ZDCXL-SF-02-03-02)
万方数据