セボフルラン誘発性神経細胞死におけるNCOA4-フェリチンファジー-GPX4経路を介した発達神経細胞の鉄依存性細胞死

Sevoflurane is a cornerstone of pediatric anesthesia but poses risks for neurodevelopmental toxicity. While dysregulation of iron metabolism and autophagy have been implicated, the precise molecular link, particularly the role of NCOA4-mediated ferritinophagy in driving ferroptosis, remains a critical knowledge gap. This study aimed to determine whether and how the NCOA4-ferritinophagy-GPX4 axis mediates sevoflurane-induced neuronal ferroptosis in the developing brain. The involvement of NCOA4-mediated ferritinophagy and ferroptosis in sevoflurane-induced neurotoxicity was examined using both in vitro PC12 cell models and in vivo neonatal Sprague-Dawley rat models. In vitro, PC12 cells were exposed to sevoflurane and subsequently treated with Ferrostatin-1 (Fer-1), 3-Methyladenine (3-MA), or NCOA4-targeted siRNA. Assessments included measurements of cell viability, oxidative stress markers, and the expression levels of ferroptosis-related genes and proteins. In in vivo, neonatal rats were exposed to sevoflurane, followed by evaluation of hippocampal damage and cognitive function using Western blot analysis, hematoxylin and eosin staining, immunohistochemistry, and the Morris water maze test. Exposure to sevoflurane significantly decreased cell viability and intracellular glutathione levels while increasing levels of reactive oxygen species, malondialdehyde, and ferrous iron levels in PC12 cells. Expression of NCOA4 was upregulated, whereas GPX4 and ferritin expression were downregulated. Among the treatments, Fer-1 demonstrated greater efficacy in mitigating these changes compared to 3-MA or NCOA4 silencing. In neonatal rats, sevoflurane induced hippocampal neuronal damage, elevated NCOA4 expression and LC3-II/LC3-I ratio, reduced GPX4 and ferritin levels, and impaired spatial learning and memory. Fer-1 conferred superior neuroprotective effects compared to 3-MA. Sevoflurane induces ferroptotic neuronal death in the developing brain through activation of the NCOA4-ferritinophagy-GPX4 pathway. These findings highlight the vulnerability of the developing hippocampus to disruptions in iron metabolism and ferroptosis, and underscore the potential of ferroptosis-targeted neuroprotective strategies in pediatric anesthesia.