Electroacupuncture alleviates ferroptosis through miR-145-5p/ACSL4 axis to reduce post-reperfusion brain injury in ischemic stroke.

BACKGROUND: Ferroptosis induced by reperfusion in ischemic stroke (IS) represent core mechanisms that exacerbate brain injury and neurological dysfunction. Electroacupuncture (EA) is widely used in neurological rehabilitation, but its specific mechanism for improving reperfusion injury in ischemic stroke remains unclear. METHODS: We established a middle cerebral artery occlusion (MCAO) mouse model, the impacts of EA on infarction volume, cerebral cortex damage, and neuronal apoptosis were observed using pathological staining. Additionally, an oxygen-glucose deprivation/reoxygenation (OGD/R) SH-SY5Y cell model were established. miR-145-5p and Acyl-CoA synthetase long-chain family member 4 (ACSL4) expression were assessed through qRT-PCR, and the targeted regulatory relationship between the two was validated by a dual luciferase assay. CCK-8 assay, EdU staining, lactate dehydrogenase (LDH) assay kit, flow cytometry, and Calcein/PI staining were applied to detected cell proliferation and damage. Markers associated with oxidative stress and ferroptosis were detected using different assay kits, while ferroptosis-related proteins levels were assessed through Western blot. RESULTS: In vivo, EA reduced cerebral infarction volume in MCAO mice, lowered neurological deficit scores, alleviated cerebral edema and blood-brain barrier damage, and inhibited neuronal apoptosis. MiR-145-5p was downregulated in MCAO mice, EA treatment upregulated miR-145-5p and downregulated ACSL4 expression, and inhibited the excessive production of NO and NOS isoforms expression in ischemic brain tissue, thereby improving oxidative stress and ferroptosis. Silencing miR-145-5p or overexpressing ACSL4 both weakened the beneficial impact of EA on MCAO mice. OGD/R diminished viability and proliferation capacity in SH-SY5Y cells, increased LDH release, and elevated apoptosis rates. MiR-145-5p overexpression suppressed ACSL4 expression, ameliorated oxidative stress and ferroptosis, and mitigated OGD/R-induced cellular damage, whereas ACSL4 overexpression reversed this protective effect. CONCLUSION: EA alleviates oxidative stress and ferroptosis in IS after reperfusion through upregulating miR-145-5p and suppressing ACSL4 expression.