Cerebral ischemia–reperfusion injury triggers mitochondrial dysfunction and oxidative stress, exacerbating neuronal apoptosis. Emerging evidence highlights hydrogen sulfide (H₂S) as a gasotransmitter modulating redox balance, autophagy, and apoptosis. This study investigates the neuroprotective mechanisms of Enriched Environment (EE) against ischemic injury, focusing on mitochondrial dynamics and H₂S-mediated pathways. Using MCAO mice and OGD/R-treated SH-SY5Y neurons, interventions targeting H₂S synthesis, hypoxia-inducible factor 1-alpha (HIF-1α), and mitophagy were implemented. Behavioral, histological, and molecular analyses demonstrated EE significantly improved neurological outcomes, suppressed apoptosis, and attenuated oxidative damage (reduced MDA, elevated MnSOD/glutathione). Mechanistically, EE enhanced mitophagy via dual pathways: canonical PINK1/parkin-mediated mitochondrial clearance, corroborated by transmission electron microscope and LC3B/parkin colocalization, and non-canonical HIF-1α/BNIP3L axis activation. Transcriptomic and Co-immunoprecipitation (Co-IP) data revealed EE upregulated endogenous H₂S biosynthesis post-injury by promoting dopamine-induced calcium influx, which activated calmodulin-dependent signaling to stimulate cystathionine β-synthase/γ-lyase expression. Pharmacological blockade of H₂S synthesis or HIF-1α abolished mitochondrial protection, confirming H₂S as a central mediator. Notably, H₂S exerted antiapoptotic effects by restoring mitochondrial integrity through synergistic mitophagy activation and oxidative stress mitigation. These findings propose a novel neuroprotective cascade: EE-induced dopaminergic signaling potentiates H₂S production, which coordinates PINK1/parkin and HIF-1α/BNIP3L pathways to eliminate dysfunctional mitochondria, thereby preserving neuronal homeostasis. This study elucidates therapeutic potential of EE via H₂S-driven mitochondrial quality control, offering insights for ischemic brain injury intervention.

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.