Xu Xuan, Li Runqian, Li Shengnan, Wei Qin, Yu Fuchao, Ma Genshan, Tong Jiayi
Department of Cardiology, Zhongda Hospital, Southeast University, 87 Dingjiaqiao, Nanjing 210009, P.R. China.
School of medicine, Southeast University, Nanjing 210009, P. R. China.
Int J Biol Sci. 2025 Jul 28;21(11):5079-5096. doi: 10.7150/ijbs.107402. eCollection 2025.
Myocardial ischemia/reperfusion (MI/R) injury remains a major challenge in cardiovascular therapeutics, with pathogenesis closely associated with reactive oxygen species (ROS) accumulation and ferroptosis. While sphingosine-1-phosphate receptors (S1PRs) activation demonstrates cardioprotective potential against MI/R injury, its mechanistic relationship with redox homeostasis and ferroptotic pathways requires elucidation. Using hypoxia/reoxygenation (H/R)-treated cardiomyocytes, we investigated S1P-mediated regulation of , , and transcription through pharmacological inhibition of the S1PRs/Src/STAT3 signaling pathway. Mechanistic insights into S1PRs/Src/STAT3-mediated transcriptional control were obtained through integrated bioinformatics, dual-luciferase reporter assays, chromatin immunoprecipitation, and molecular profiling (qRT-PCR/ Western blotting). In a MI/R mouse model, the therapeutic effects of S1P and Fingolimod were determined using echocardiography, TTC staining, fluorescent probes, and TEM, with mechanisms validated by Western blotting and qRT-PCR. In vitro studies revealed that S1PRs activation (via S1P or Fingolimod) promoted STAT3 phosphorylation and nuclear translocation through Src signaling, thereby enhancing transcriptional upregulation of , , and . This signaling cascade attenuated H/R-induced ROS generation, mitochondrial damage, and ferroptosis markers, with S1PR1 demonstrating predominant cytoprotection. Chromatin studies confirmed p-STAT3 binding to antioxidant/ferroptosis-related gene promoters. In vivo findings mirrored cellular observations, showing S1PRs agonism significantly improved cardiac function, reduced infarct size, and suppressed myocardial lipid peroxidation compared with untreated controls. Our findings establish that S1PRs signaling confers cardioprotection against MI/R injury through STAT3 phosphorylation-mediated transcriptional activation of antioxidant defense systems and ferroptosis suppression. This mechanistic insight positions S1PRs modulation as a promising therapeutic strategy for ischemic cardiomyopathy.
心肌缺血/再灌注（MI/R）损伤仍然是心血管治疗中的一项重大挑战，其发病机制与活性氧（ROS）积累和铁死亡密切相关。虽然1-磷酸鞘氨醇受体（S1PRs）激活显示出对MI/R损伤的心脏保护潜力，但其与氧化还原稳态和铁死亡途径的机制关系尚待阐明。我们使用缺氧/复氧（H/R）处理的心肌细胞，通过对S1PRs/Src/STAT3信号通路的药理学抑制，研究了S1P介导的对 、 和 转录的调控。通过综合生物信息学、双荧光素酶报告基因测定、染色质免疫沉淀和分子分析（qRT-PCR/蛋白质免疫印迹），获得了对S1PRs/Src/STAT3介导的转录控制的机制性见解。在MI/R小鼠模型中，使用超声心动图、TTC染色、荧光探针和透射电子显微镜确定了S1P和芬戈莫德的治疗效果，并通过蛋白质免疫印迹和qRT-PCR验证了其机制。体外研究表明，S1PRs激活（通过S1P或芬戈莫德）通过Src信号促进STAT3磷酸化和核转位，从而增强 、 和 的转录上调。该信号级联减弱了H/R诱导的ROS生成、线粒体损伤和铁死亡标志物，其中S1PR1表现出主要的细胞保护作用。染色质研究证实p-STAT3与抗氧化/铁死亡相关基因启动子结合。体内研究结果与细胞观察结果一致，表明与未处理的对照组相比，S1PRs激动剂显著改善了心脏功能，减小了梗死面积，并抑制了心肌脂质过氧化。我们的研究结果表明，S1PRs信号通过STAT3磷酸化介导的抗氧化防御系统转录激活和铁死亡抑制，赋予对MI/R损伤的心脏保护作用。这一机制性见解将S1PRs调节定位为缺血性心肌病的一种有前景的治疗策略。
