Enriched Environment Suppresses Neuronal Ferroptosis Through SIRT1/AKT/GSK3β-Dependent Glycogen Metabolic...

Neuronal ferroptosis is a key contributor to secondary brain injury following cerebral ischemia, yet the metabolic mechanisms governing this process remain poorly understood. Enriched environment (EE) is a housing paradigm that provides enhanced sensory, cognitive, and social stimulation through complex physical surroundings and increased opportunities for voluntary activity. Our preliminary data indicate that EE confers cerebroprotection against ischemia-induced ferroptosis; however, whether this effect is associated with glycogen metabolic regulation and the underlying molecular pathways has not been elucidated. This study aimed to determine whether EE may influence ferroptosis-associated pathways, potentially via Sirtuin 1 (SIRT1)/protein kinase B (AKT)/glycogen synthase kinase-3β (GSK3β)-related mechanisms of glycogen metabolism. Using a mouse model of middle cerebral artery occlusion (MCAO) and an oxygen-glucose deprivation/reoxygenation (OGD/R) cellular model, we performed behavioral assessments, molecular and biochemical analyses, and pharmacological interventions to elucidate mechanistic pathways. EE was associated with improved neurological outcomes and reduced infarct volume after ischemia. Mechanistically, EE appeared to activate the SIRT1/AKT pathway and increase the inhibitory phosphorylation of GSK3β and relieving its suppressive effect on glycogen synthase, which may underlie the observed increase in glycogen levels within ischemic brain tissue. Pharmacological inhibition of SIRT1 largely diminished these metabolic and neuroprotective benefits. Consistently, at the cellular level, SIRT1 overexpression contributed to the restoration of glycogen metabolism and robustly attenuated ferroptosis under ischemic conditions. Collectively, these findings suggest that EE may attenuate ferroptosis-related pathways possibly involving SIRT1/AKT/GSK3β-dependent glycogen metabolic remodeling, providing a novel metabolic perspective on EE-induced cerebroprotection and highlighting SIRT1-centered regulation of glycogen metabolism as a potential therapeutic target for ischemic stroke.