目的 探究漆黄素通过激活沉默信息调节因子1（SIRT1）/核因子E2相关因子2（Nrf2）信号通路对急性呼吸窘迫综合征大鼠铁死亡的影响。方法 将SD大鼠随机分为对照组、模型组以及漆黄素1、2、4 mg/kg组和漆黄素（4 mg/kg）＋SIRT1抑制剂（10 mg/kg EX-527）组，每组各14只。漆黄素、SIRT1抑制剂于造模前30 min ip给药，对照组、模型组ip给予等量生理盐水。除对照组外，其余各组大鼠均采用气管内滴注脂多糖法建立急性呼吸窘迫综合征模型。检测支气管肺泡灌洗液（BALF）中炎性因子白细胞介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）水平；测定肺组织湿/干质量比（W/D）；HE染色观察肺组织病理改变；检测肺组织中铁死亡相关指标活性氧（ROS）、铁、谷胱甘肽（GSH）、丙二醛（MDA）水平；免疫印迹法检测肺组织中SIRT1/Nrf2信号通路相关蛋白表达。结果 与模型组比较，漆黄素各剂量组BALF中IL-6、TNF-α水平降低，肺组织W/D比值降低，肺组织中ROS、铁、MDA水平降低，GSH水平升高，肺组织中SIRT1、核Nrf2蛋白水平升高（P<0.05），且4 mg/kg漆黄素干预的改善效果更显著；在4 mg/kg漆黄素干预的基础上增加SIRT1抑制剂后，漆黄素的改善作用被削弱。结论 漆黄素对脂多糖诱导的急性呼吸窘迫综合征有保护作用，能够改善铁死亡，可能是通过激活SIRT1/Nrf2信号通路实现的。

Objective To investigate the influence of fisetin on ferroptosis in rats with acute respiratory distress syndrome (ARDS) by activating the silent information regulation 1 (SIRT1)/nuclear factor E2-related factor 2 (Nrf2) signaling pathway. Methods SD rats were randomly divided into control group, model group, fisetin (1, 2, and 4 mg/kg) groups, and 4 mg/kg fisetin + SIRT1 inhibitor (10 mg/kg EX-527) group, each group had 14 rats. Fisetin and SIRT1 inhibitor were ip administered with 30 min before modeling, and the control group and model group were ip administered with the same amount of normal saline. Except the control group, the rats in other groups were used to establish the ARDS model by intratracheal instillation of lipopolysaccharide (LPS). Levels of inflammatory factor IL-6 and TNF-α in BALF were detected. The wet/dry mass ratio (W/D) of lung tissue was measured. Pathological changes in lung tissue treated by HE staining were observed. The levels of reactive oxygen species (ROS), iron, GSH, and MDA in lung tissue were measured. The expression of SIRT1/Nrf2 signaling pathway related proteins in lung tissue were detected by Western blotting method. Results Compared with the model group, the levels of IL-6 and TNF-α in the BALF of fisetin groups were decreased, the W/D ratio in lung tissue were decreases, the levels of ROS, iron, and MDA in lung tissue were decreased, while GSH levels were increased, and the levels of SIRT1 and nuclear Nrf2 proteins in lung tissue were increased (P < 0.05). Moreover, the improvement effect of 4 mg/kg fisetin intervention was more obvious. After the addition of SIRT1 inhibitor on the basis of 4 mg/kg fisetin intervention, the improvement effect of 4 mg/kg fisetin was weakened. Conclusion Fisetin has protection on LPS induced ARDS and can improve ferroptosis, which may be achieved by activating SIRT1/Nrf2 signaling pathway.

R285

四川省卫生健康科研课题普及项目（19PJ1182）