Neuronal ferroptosis plays a key role in neurologic deficits post intracerebral hemorrhage (ICH). However, the endogenous regulation of rescuing ferroptotic neurons is largely unexplored. Here, we analyzed the integrated alteration of metabolomic landscape after ICH using LC-MS and MALDI-TOF/TOF MS, and demonstrated that aconitate decarboxylase 1 (Irg1) and its product itaconate, a derivative of the tricarboxylic acid cycle, were protectively upregulated. Deficiency of Irg1 or depletion of neuronal Irg1 in striatal neurons was shown to exaggerate neuronal loss and behavioral dysfunction in an ICH mouse model using transgenic mice. Administration of 4-Octyl itaconate (4-OI), a cell-permeable itaconate derivative, and neuronal Irg1 overexpression protected neurons in vivo. In addition, itaconate inhibited ferroptosis in cortical neurons derived from mouse and human induced pluripotent stem cells in vitro. Mechanistically, we demonstrated that itaconate alkylated glutathione peroxidase 4 (GPx4) on its cysteine 66 and the modification allosterically enhanced GPx4’s enzymatic activity by using a bioorthogonal probe, itaconate-alkyne (ITalk), and a GPx4 activity assay using phosphatidylcholine hydroperoxide. Altogether, our research suggested that Irg1/itaconate-GPx4 axis may be a future therapeutic strategy for protecting neurons from ferroptosis post ICH.

神经元铁死亡在脑出血（ICH）后神经功能缺损中起着关键作用。然而，拯救铁死亡神经元的内源性调节在很大程度上尚未被探索。在这里，我们使用 LC-MS 和 MALDI-TOF/TOF MS 分析了 ICH 后代谢组景观的综合变化，并证明乌头酸脱羧酶 1 (Irg1) 及其产物衣康酸（三羧酸循环的衍生物）被保护性上调。在转基因小鼠的 ICH 小鼠模型中，纹状体神经元中Irg1的缺乏或神经元Irg1的缺失会加剧神经元损失和行为功能障碍。给予衣康酸 4-辛酯 (4-OI)（一种细胞可渗透的衣康酸酯衍生物）和神经元Irg1过表达可保护体内神经元。此外，衣康酸在体外抑制来自小鼠和人类诱导多能干细胞的皮质神经元的铁死亡。从机制上讲，我们通过使用生物正交探针衣康酸-炔 (ITalk) 和使用氢过氧化磷脂酰胆碱的 GPx4 活性测定，证明了衣康酸烷基化谷胱甘肽过氧化物酶 4 (GPx4) 在其半胱氨酸 66 上的变构增强了 GPx4 的酶活性。总而言之，我们的研究表明 Irg1/衣康酸-GPx4 轴可能是未来 ICH 后保护神经元免受铁死亡的治疗策略。