Semaglutide Mitigates Ischemic Brain Injury by Inhibiting Ferroptosis via Modulation of FoXO1 and DRP1 Pathways.

Multiple pathogenic processes contribute to cerebral ischemia-reperfusion injury (CIRI); however, their relative importance and sequence remain unclear, warranting further investigation. Although our previous studies showed that inhibiting ferroptosis mitigates brain damage after ischemic stroke, the crosstalk among intracellular pathways remains poorly understood. The protective effects of semaglutide, a novel glucagon-like peptide-1 receptor agonist (GLP-1RA), in ischemic stroke have yet to be fully elucidated. In this study, bioinformatics analysis was conducted to predict the potential therapeutic mechanisms of semaglutide in CIRI, highlighting the involvement of the FoXO1-autophagy pathway and mitochondrial dynamics. A rat's middle cerebral artery occlusion/reperfusion (MCAO/R) model was established to validate these predictions. Histopathological examination demonstrated that semaglutide alleviated pathological damage and reduced neuronal apoptosis. Using Western blotting, RT-PCR, immunofluorescence, and ELISA, we assessed key markers-GLP-1R, FoXO1, Beclin1, DRP1, Mfn2, ATP, and ROS-in the ischemic penumbra. The results showed that semaglutide inhibited autophagy (Beclin1), suppressed mitochondrial fission (DRP1), promoted mitochondrial fusion (Mfn2), and improved mitochondrial function, as reflected by increased ATP production and reduced ROS levels. Furthermore, we investigated the involvement of FoXO1 and mitochondrial function in the regulation of ferroptosis. The findings suggest that semaglutide inhibits ferroptosis by activating GLP-1R, thereby modulating the intracellular FoXO1/GPX4 and DRP1/ACSL4 signaling pathways. In summary, semaglutide acts through GLP-1R to regulate FoXO1-mediated autophagy, mitochondrial dynamics, and ferroptosis, as well as to modulate DRP1-dependent mitochondrial fission and ferroptosis. Together, these mechanisms account for its protective effects against ischemic stroke.