摘要
目的 观察亚精胺(SPD)对脂多糖(LPS)诱导的脓毒症心肌损伤的保护作用及机制研究.方法 在动物水平上,C57BL/6小鼠随机分为:空白对照组(Control)、LPS组(10 mg/kg)、LPS+SPD组(5 mmol/L),应用HE染色观察小鼠心肌组织形态变化,透射电镜观察心肌线粒体超微结构.在细胞水平上,根据处理方式及10和20 μmol/L SPD,将大鼠H9c2心肌细胞随机分为:Control、LPS、LPS+SPD 10、LPS+SPD 20组,应用CCK-8试剂盒检测细胞活力,乳酸脱氢酶试剂盒检测细胞LDH水平、ELISA测定心肌细胞cTNI的变化,Western blot检测凋亡蛋白Bax、Bcl-2、Cleaved-caspase3表达水平及铁死亡相关蛋白SLC7A11、GPX4表达水平,应用荧光探针检测细胞活性氧ROS及Fe2+水平,JC-1染色法检测细胞线粒体膜电位.结果 小鼠心肌组织HE染色及透射电镜结果显示:Control组心肌及线粒体结构正常,LPS处理后,小鼠心肌组织结构紊乱、间隙变大,并且线粒体明显损伤,出现肿大、空泡化及坏死等现象,SPD处理可改善LPS导致的心肌及线粒体损伤.细胞水平上,与空白对照组相比,LPS组细胞活力明显下降(P<0.05),LDH、cTNI水平明显升高(P<0.05),细胞凋亡蛋白Bax、Cleaved-caspase3水平增加(P<0.05),Bcl-2蛋白表达水平下降(P<0.05),SLC7A11、GPX4蛋白的表达水平降低(P<0.05),细胞活性氧ROS及Fe2+水平增加(P<0.05),线粒体膜电位下降;经SPD预处理后,H9c2细胞活力明显增加(P<0.05),LDH、cTNI水平降低(P<0.05),细胞凋亡蛋白Bax,Cleaved-caspase3的表达水平降低(P<0.05),Bcl-2蛋白表达水平增加(P<0.05),铁死亡相关蛋白SLC7A11、GPX4的表达水平增加(P<0.05),细胞活性氧ROS及Fe2+水平降低(P<0.05),线粒体膜电位上升.结论 SPD可减轻脓毒症心肌损伤,其机制与降低细胞凋亡、抑制细胞活性氧ROS产生、减轻铁死亡有关.
Abstract
Objective To investigate the protective effect of spermidine against lipopolysaccharide(LPS)-induced myocardial injury in mice and the underlying mechanism.Methods C57BL/6 mice subjected to intraperitoneal LPS injection with or without pretreatment with daily gavage of spermidine for 2 weeks were examined for myocardial pathologies using HE staining and transmission electron microscopy.In the cell experiment,cultured rat cardiomyocytes(H9c2 cells)were pretreated with 10 or 20 μmol/L spermidine before LPS exposure for 2 h,and the changes in cell viability and levels of lactate dehydrogenase(LDH)and cardiac troponin Ⅰ(cTNI)were assessed using CCK-8 kit,LDH detection kit and ELISA,respectively.Western blotting was performed to detect the changes in the expressions of Bax,Bcl-2,cleaved caspase-3,SLC7A11 and GPX4;the changes in reactive oxygen species(ROS)and Fe2+ levels were detected using fluorescent probes,and mitochondrial membrane potential of the cells was measured using JC-1 staining.Results Treatment of the mice with LPS induced obvious myocardial and mitochondrial damages,which were significantly alleviated by pretreatment with spermidine.In H9c2 cells,LPS exposure significantly lowered the cell viability,increased LDH and cTNI levels and expressions of Bax and cleaved caspase-3 levels,decreased expressions of Bcl-2,SLC7A11 and GPX4,increased ROS production and Fe2+ level(P<0.05),and lowered mitochondrial membrane potential(all P<0.05).These effects were significantly alleviated by SPD pretreatment of the cells prior to LPS exposure.Conclusion Spermidine alleviates LPS-induced myocardial injury by suppressing cell apoptosis and inhibiting cellular ROS production and ferroptosis.
基金项目
陕西省自然科学基金(2023-JC-QN-0938)
陕西省科研项目(2018SF-095)
西安市卫生健康委项目(2020qn09)
国家科技期刊平台
NSTL
维普
万方数据