Study on the role and mechanism of intermittent theta burst stimulation (iTBS) induced N-acetylaspartylglutamate (NAAG) in suppressing ferroptosis in ischemic stroke

This study investigates the mechanism through which intermittent theta burst stimulation (iTBS) inhibits ferroptosis in ischemic stroke by inducing N-acetylaspartylglutamate (NAAG). In SD rats subjected to middle cerebral artery occlusion (MCAO), iTBS treatment significantly decreased ischemia–reperfusion (I/R) injury, improving motor, coordination, spatial memory abilities and Cognitive Impairment by enhancing synaptic function and neuronal repair. Western blot analysis showed that in MCAO rats treated with iTBS, GPX4 protein expression increased, while ACSL4, TFRC, and DMT1 protein levels decreased. Furthermore, malondialdehyde (MDA), a product of lipid peroxidation, was significantly reduced. The antioxidant levels of SOD and GSH were notably elevated, while the content of iron ions decreased. These results indicate that iTBS effectively inhibits ferroptosis by reducing oxidative stress and iron accumulation. Metabolomic analysis has revealed a novel finding that iTBS increases the levels of NAAG and inhibits its rate-limiting enzyme FOLH1 (GCP-II), thereby decreasing excitatory glutamate production, improving glutathione metabolism, and subsequently suppressing ferroptosis. In vitro experiments demonstrated that NAAG and 2-PMPA (a FOLH1 inhibitor) improved cell survival and antioxidant capacity in an oxygen-glucose deprivation/reperfusion (OGD/R) model, suppressing ferroptosis. In conclusion, iTBS exerts a neuroprotective effect by regulating the synthesis and metabolism of NAAG, enhancing antioxidant capacity and iron metabolism, and delaying ferroptosis. This research provides new insights into potential treatments for Post-Stroke Cognitive Impairment.