本研究旨在探讨过氧化物酶体增殖物激活受体α(PPAR-α),一种已知的铁凋亡抑制剂,心肌缺血/再灌注损伤(MIRI)及其相关机制。建立体内和体外MIRI模型。我们的结果表明,PPAR-α的激活减少了心肌梗死的大小,维持心脏功能,降低血清肌酸激酶同工酶(CK-MB)含量,乳酸脱氢酶(LDH),和Fe2+在缺血/再灌注(I/R)处理的小鼠中。此外,H&E染色结果,DHE染色,TUNEL染色,透射电镜显示PPAR-α的激活抑制MIRI诱导的心脏组织和线粒体损伤。还发现PPAR-α的激活减弱了MIRI诱导的铁凋亡,如丙二醛的减少所示。总铁,和活性氧(ROS)。体外实验表明,细胞内丙二醛含量,总铁,LDH,活性氧(ROS),脂质ROS,氧化型谷胱甘肽二硫化物(GSSG),缺氧/复氧(A/R)处理的H9c2细胞中PPAR-α的激活使Fe2减少,而PPAR-α激活后细胞活力和GSH增加。此外,铁凋亡标志物蛋白质水平的变化进一步证实了PPAR-α活化对MIRI诱导的铁凋亡的有益作用。此外,免疫荧光和双荧光素酶报告基因分析的结果表明,PPAR-α通过与14-3-3η启动子结合实现其活性,提高其表达水平。此外,PPAR-α的心脏保护作用可被pAd/14-3-3η-shRNA或化合物C11(14-3-3η抑制剂)消除。总之,我们的结果表明,铁中毒在加重MIRI中起关键作用,PPAR-α/14-3-3η途径介导的铁凋亡和线粒体损伤可能是针对MIRI的有效治疗靶标。
This study aimed to explore the effects of peroxisome proliferator-activated receptor α (PPAR-α), a known inhibitor of ferroptosis, in Myocardial ischemia/reperfusion injury (MIRI) and its related mechanisms. In vivo and in vitro MIRI models were established. Our results showed that activation of PPAR-α decreased the size of the myocardial infarct, maintained cardiac function, and decreased the serum contents of creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and Fe2+ in ischemia/reperfusion (I/R)-treated mice. Additionally, the results of H&E staining, DHE staining, TUNEL staining, and transmission electron microscopy demonstrated that activation of PPAR-α inhibited MIRI-induced heart tissue and mitochondrial damage. It was also found that activation of PPAR-α attenuated MIRI-induced ferroptosis as shown by a reduction in malondialdehyde, total iron, and reactive oxygen species (ROS). In vitro experiments showed that intracellular contents of malondialdehyde, total iron, LDH, reactive oxygen species (ROS), lipid ROS, oxidized glutathione disulphide (GSSG), and Fe2+ were reduced by the activation of PPAR-α in H9c2 cells treated with anoxia/reoxygenation (A/R), while the cell viability and GSH were increased after PPAR-α activation. Additionally, changes in protein levels of the ferroptosis marker further confirmed the beneficial effects of PPAR-α activation on MIRI-induced ferroptosis. Moreover, the results of immunofluorescence and dual-luciferase reporter assay revealed that PPAR-α achieved its activity via binding to the 14-3-3η promoter, promoting its expression level. Moreover, the cardioprotective effects of PPAR-α could be canceled by pAd/14-3-3η-shRNA or Compound C11 (14-3-3η inhibitor). In conclusion, our results indicated that ferroptosis plays a key role in aggravating MIRI, and PPAR-α/14-3-3η pathway-mediated ferroptosis and mitochondrial injury might be an effective therapeutic target against MIRI.