ABSTRACT NUMBER: ESOC2026A1777 MECHANISTIC IMPLICATIONS OF FERROPTOSIS MODULATION IN SUB-ACUTE BRAIN ISCHEMIA

Abstract Background and aims Ferroptosis plays a pivotal role in stroke pathophysiology and ischemia-reperfusion injury. Despite its therapeutic potential, ferroptosis-specific transcriptomic and functional changes in the subacute stroke phase remain poorly characterised. Here, we aim to identify ferroptosis-specific pathomechanistic changes post-stroke through targeted pharmacological and genetic modulation to identify mechanistic biomarkers and potential therapeutic targets. Methods Using mice subjected to middle cerebral artery occlusion, we conducted a dual pharmacological strategy inhibiting the key ferroptosis suppressor GPX4, and the principal driver ACSL4. Pathomechanistic, behavioral, and transcriptomic outcomes were assessed subacutely. Additionally, further mechanistic analyses were conducted using a conditional GPX4 knockout model selectively targeting glutamatergic neurons. Results Transcriptomic profiling and gene set enrichment analysis revealed that ferroptosis modulation upregulated pathways associated with neuromotor activity, synaptic plasticity, and neuro-regeneration, while neuroinflammatory and lipid metabolic signalling was supressed. These molecular signatures were validated experimentally. Behavioral analysis and immunohistochemistry confirmed enhanced neuromotor performance, reduced inflammatory response, astrocyte reactivity, and increased post-synaptic capacity following pharmacological ferroptosis modulation. Additionally, characterization of a conditional deletion of GPX4 in glutamatergic neurons exacerbated ischemic injury, resulting in larger infarct volumes, worsened locomotor outcome, increased astrocyte reactivity and reduced synaptic capacity, highlighting the key mechanistic role of GPX4 in post-stroke recovery. Conclusions Our findings establish ferroptosis as a key modulator of post-stroke neuronal plasticity and functional recovery, extending beyond its canonical role in lipid peroxidation and oxidative damage. Pharmacological modulation of ferroptosis promotes synaptic remodelling and neuronal regeneration, while genetic deletion of GPX4 significantly worsened post-stroke outcomes. These results highlight ferroptosis targeted interventions as promising therapeutic strategies. Conflict of interest Svenja Erkelenz:Nothing to disclose Sebastian Vonhof:Nothing to disclose Rebecca Szepanowski: Nothing to disclose Ana Casas: Nothing to disclose Christoph Kleinschnitz: Nothing to disclose Jasmin Bahr: Nothing to disclose Jeremy Ramseger: Nothing to disclose none of the authors have something to disclose