Li Ling-Yu, Zhou Chun-Xue, Han Bing, Elsheikha Hany M, Qiu Hui-Jie, An Xu-Dian, Zeng Ting, Liu Dai-Ang, Yang Qing, Zhu Xing-Quan, Zhou Huai-Yu
Department of Pathogen Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong Province, PR China.
Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Loughborough, UK.
Virulence. 2025 Dec;16(1):2530164. doi: 10.1080/21505594.2025.2530164. Epub 2025 Jul 16.
The protozoan parasite employs intricate mechanisms to exploit host cells while sustaining their viability, yet its interaction with ferroptosis - an iron-dependent cell death driven by lipid peroxidation - remains poorly defined. Here, we show infection induces ferroptotic hallmarks in RAW264.7 macrophages, including elevated lactate dehydrogenase release, labile Fe accumulation, reactive oxygen species (ROS) generation, and lipid peroxidation. Molecular analyses revealed infection-induced downregulation of ferroptosis suppressor GPX4 and upregulation of pro-ferroptotic ACSL4 in macrophages and mice. Mechanistically, the SLC7A11/GPX4 axis governed parasite growth: knockdown of these genes promoted replication, whereas overexpression restricted proliferation. Pharmacological studies showed ferroptosis inhibitor Fer-1 suppressed intracellular parasite proliferation. Notably, GPX4 inhibitor RSL3 exhibited context-dependent effects: pre-infection treatment enhanced replication, while post-infection administration inhibited growth. Direct RSL3 exposure induced time-dependent growth arrest in extracellular tachyzoites, associated with disrupted transcriptomes, increased lipid ROS, and downregulated parasite antioxidant genes (, , ), indicating redox homoeostasis impairment. In vivo murine studies corroborated this biphasic effect: therapeutic RSL3 administration post-infection significantly reduced parasite burdens across multiple organs (spleen, liver, kidney, brain) and improved survival rates, while prophylactic pretreatment exacerbated disease progression. We propose RSL3 exerts direct parasiticidal effects via oxidative damage but also enables early nutrient acquisition from ferroptosis-compromised host cells. These findings establish ferroptosis as a critical node in pathogenesis, highlighting the parasite's hijacking of host iron-lipid metabolism. The dual role of ferroptosis regulators underscores the host-pathogen metabolic complexity and positions the SLC7A11/GPX4 axis as a promising therapeutic target.
这种原生动物寄生虫采用复杂的机制来利用宿主细胞，同时维持其活力，然而它与铁死亡（一种由脂质过氧化驱动的铁依赖性细胞死亡）之间的相互作用仍不清楚。在这里，我们表明感染会在RAW264.7巨噬细胞中诱导铁死亡特征，包括乳酸脱氢酶释放增加、不稳定铁积累、活性氧（ROS）生成和脂质过氧化。分子分析显示，感染会导致巨噬细胞和小鼠中铁死亡抑制因子GPX4的下调以及促铁死亡因子ACSL4的上调。从机制上讲，SLC7A11/GPX4轴控制着寄生虫的生长：敲低这些基因会促进寄生虫复制，而过度表达则会限制其增殖。药理学研究表明，铁死亡抑制剂Fer-1可抑制细胞内寄生虫的增殖。值得注意的是，GPX4抑制剂RSL3表现出依赖于环境的效应：感染前治疗会增强寄生虫复制，而感染后给药则会抑制其生长。直接暴露于RSL3会导致细胞外速殖子出现时间依赖性的生长停滞，这与转录组紊乱、脂质ROS增加以及寄生虫抗氧化基因（、、）下调有关，表明氧化还原稳态受损。体内小鼠研究证实了这种双相效应：感染后给予治疗性RSL3可显著降低多个器官（脾脏、肝脏、肾脏、大脑）中的寄生虫负荷并提高存活率，而预防性预处理则会加剧疾病进展。我们认为RSL3通过氧化损伤发挥直接杀寄生虫作用，但同时也能从铁死亡受损的宿主细胞中早期获取营养。这些发现确立了铁死亡是发病机制中的一个关键节点，突出了寄生虫对宿主铁脂质代谢的劫持。铁死亡调节因子的双重作用强调了宿主 - 病原体代谢的复杂性，并将SLC7A11/GPX4轴定位为一个有前景的治疗靶点。
