Silver nanoparticles induce ferroptosis via iron dyshomeostasis and system Xc⁻/GPX4 axis dysregulation in HT22 cells

Silver nanoparticles (AgNPs) are widely used for their antimicrobial properties, yet their neurotoxic mechanisms remain under-explored. Ferroptosis, an iron-dependent regulated cell-death pathway implicated in neurological disorders, has not been fully considered in AgNPs-induced neuronal injury. Here, exposures of HT22 mouse hippocampal neurons to AgNPs (2-8 µg/mL) or AgNO₃ (0.15-0.6 µg/mL) reduce viability, disrupt iron homeostasis, trigger lipid peroxidation, downregulate GPX4 and upregulate SLC7A11 (system Xc⁻/GPX4 axis), and alter ferroptosis-related proteins (TFRC, FTH1, FTL, ACSL4, COX2). Ferroptosis inhibitors (deferoxamine, Ferrostatin-1) mitigate these effects. Notably, although AgNO₃ induced greater Ag⁺ uptake, AgNPs produced equivalent ferroptotic responses, suggesting nanoparticle-specific mechanisms beyond ionic release. These findings echo our previous in vivo data showing that AgNPs exposure impairs learning and memory in mice. Collectively, our results indicate that AgNPs provoke ferroptosis in hippocampal neurons via iron-dysregulation and antioxidant failure, and our inhibitor-based in vitro study offers mechanistic insight that may guide future therapeutic strategies.