Reactive oxygen species (ROS) produced in the ischemic myocardium can induce cardiomyocyte injury and death, resulting in cardiac remodeling. Ferroptosis, known as a newly type of cell death caused by iron-dependent oxidative stress, which is an essential death mechanism in cardiomyocytes. However, it is unclear whether oxidative stress products can further induce ferroptosis and aggravate cardiomyocyte injury. Geniposide (GEN), a major active component of Gardenia jasminoides J. Ellis, possesses the natural antioxidant activity and cardioprotective effect. Herein, we evaluated the role of ferroptosis in myocardial oxidative injury and the protective effect of GEN on myocardial ferroptosis. We first detected iron overload, massive ROS, and lipid peroxidation in ferric ammonium citrate (FAC)-treated cardiomyocytes, which were typical characteristics of ferroptosis. The iron overload-induced oxidative stress and ferroptosis aggravated cardiomyocyte injury, which were significantly alleviated by GEN treatment. Similar phenotypic changes of ferroptosis were consistently discovered in hydrogen peroxide (H₂O₂)-induced cells, which were reversed by GEN treatment as well. Interestingly, the RNA-binding protein Grsf1, which directly upregulated Gpx4 at the translational level, was activated by GEN following myocardial oxidative injury. The specific knockdown of Grsf1 increased their sensitivity to ferroptosis and weakened the cardioprotective effect of GEN in H₂O₂-treated cardiomyocytes. Moreover, GEN treatment reduced iron overload and lipid peroxidation in myocardial infarction (MI) rats, thereby fighting against the cardiac ischemic injury. Collectively, our study revealed the pathogenesis of oxidative stress and ferroptosis associated with myocardial ischemia, and indicated the antioxidant and anti-ferroptosis effects of GEN on preventing myocardial injury by activating the Grsf1/GPx4 axis, serving as a potential therapeutic target.

缺血心肌中产生的活性氧 (ROS) 可诱导心肌细胞损伤和死亡，从而导致心脏重塑。铁死亡，是一种由铁依赖性氧化应激引起的新型细胞死亡，是心肌细胞必不可少的死亡机制。然而，目前尚不清楚氧化应激产物是否会进一步诱导铁死亡并加重心肌细胞损伤。栀子苷（GEN），一种主要的活性成分栀子花 J. Ellis，具有天然的抗氧化活性和心脏保护作用。在此，我们评估了铁死亡在心肌氧化损伤中的作用以及GEN对心肌铁死亡的保护作用。我们首先在柠檬酸铁铵 (FAC) 处理的心肌细胞中检测到铁过载、大量 ROS 和脂质过氧化，这是铁死亡的典型特征。铁超负荷诱导的氧化应激和铁死亡加重了心肌细胞损伤，GEN治疗显着减轻了这种损伤。在过氧化氢（H ₂ O ₂) 诱导的细胞，这些细胞也被 GEN 处理逆转。有趣的是，在翻译水平上直接上调 Gpx4 的 RNA 结合蛋白 Grsf1 在心肌氧化损伤后被 GEN 激活。Grsf1的特异性敲低增加了它们对铁死亡的敏感性并削弱了GEN在H ₂ O _{2中的心脏保护作用}处理过的心肌细胞。此外，GEN 治疗可减少心肌梗死 (MI) 大鼠的铁过载和脂质过氧化，从而对抗心脏缺血性损伤。总的来说，我们的研究揭示了与心肌缺血相关的氧化应激和铁死亡的发病机制，并表明 GEN 通过激活 Grsf1/GPx4 轴来预防心肌损伤的抗氧化和抗铁死亡作用，作为潜在的治疗靶点。