瓜蒌薤白汤对博来霉素致大鼠肺纤维化内质网应激反应的影响

Effect of Gualou Xiebai Decoction on Endoplasmic Reticulum Stress in Rats with Bleomycin-induced Pulmonary Fibrosis

目的观察瓜蒌薤白汤对博来霉素诱导的肺纤维化大鼠内质网应激反应的影响,从而初步明确瓜蒌薤白汤对博来霉素诱导肺纤维化大鼠的干预机制。方法将40只大鼠随机分成正常对照组、模型组、阳性对照组、瓜蒌薤白汤组,每组10只。使用博来霉素注射法复制肺纤维化模型。隔日对阳性对照组和瓜蒌薤白汤组通过灌胃给予相应的治疗药物,各组每日灌胃1次,给药持续28 d。第28天麻醉大鼠后选择股动脉放血法处死大鼠。及时取出各组大鼠肺组织,并称质量和观察大体形态,计算肺系数,统一留取各组大鼠左下肺组织置于4%多聚甲醛溶液中固定,分别行Masson和苏木精-伊红染色观察。免疫组化法检测磷酸化蛋白激酶RNA样内质网激酶(phospho-protein kinase RNA-like ER kinase,p-PERK)、磷酸化肌醇蛋白酶1α(phospho-inositol-requiring enzyme 1α,p-IRE1α)、葡萄糖调节蛋白78(glucose regulated protein 78,GRP78)和激活转录因子6α(activating transcription factor 6α,ATF6α)在各组大鼠肺组织中的表达情况。结果模型组大鼠的肺系数相较于其他3组均明显增加(P<0.05)。阳性对照组大鼠肺系数相较于瓜蒌薤白汤组显著升高(P<0.05)。阳性对照组和瓜蒌薤白汤组大鼠炎症程度较模型组显著减轻(P<0.05),与正常对照组比较,差异无统计学意义(P>0.05);模型组大鼠纤维化程度较阳性对照组和瓜蒌薤白汤组大鼠明显增加(P<0.05)。模型组大鼠肺组织中p-PERK、p-IRE1α、GRP78和ATF6α表达水平较正常对照组显著升高(P<0.05);阳性对照组与瓜蒌薤白汤组大鼠肺组织中p-PERK、p-IRE1α、GRP78、ATF6α表达水平与正常对照组比较,差异均无统计学意义(P>0.05)。结论瓜蒌薤白汤能明显抑制博来霉素诱导的大鼠肺纤维化,其作用机制可能与抑制内质网应激有关。

Objective To investigate the effect of Gualou Xiebai Decoction on endoplasmic reticulum stress in rats with bleomycin-induced pulmonary fibrosis,and to clarify the mechanism of action of Gualou Xiebai Decoction on bleomycin-induced pulmonary fibrosis.Methods A total of 40 rats were randomly divided into normal control group,model group,positive control group,and Gualou Xiebai Decoction group,with 10 rats in each group.A rat model of pulmonary fibrosis was established by bleomycin injection.Since the next day,the rats in the positive control group and Gualou Xiebai Decoction group were given the corresponding drugs by gavage,once a day for 28 consecutive days.On day 28 after the last administration,the rats were sacrificed by exsanguination from the femoral artery after anesthesia.Lung tissue was harvested to measure the weight and perform gross observation,and the lung coefficient was calculated.The lower left lung was placed in 4%paraformaldehyde for fixation,and Masson staining and HE staining were performed.Immunohistochemistry was used to measure the expression of p-PERK,p-IRE1α,GRP78,and ATF6αin lung tissue.Results The model group had a significantly higher lung coefficient than the other three groups(P<0.05),and the positive control group had a significantly higher lung coefficient than the Gualou Xiebai Decoction group(P<0.05).Compared with the model group,the positive control group and the Gualou Xiebai Decoction group had a significant reduction in the degree of inflammation(P<0.05),while there was no significant difference in the degree of inflammation between these two groups and the normal control group(P>0.05).The model group had a significantly higher degree of pulmonary fibrosis than the positive control group and the Gualou Xiebai Decoction group(P<0.05).Compared with the normal control group,the model group had significant increases in the expression of p-PERK,p-IRE1α,GRP78,and ATF6αin lung tissue(P<0.05),while there were no significant differences in their expression between the positive control group/Gualou Xiebai Decoction group and the normal control group(P>0.05).Conclusion Gualou Xiebai Decoction can significantly inhibit bleomycin-induced pulmonary fibrosis in rats,possibly by inhibiting endoplasmic reticulum stress.