The Involvement of IFN-γ/STAT1 Signaling in the Regulation of Ferroptosis in Cerebral Ischemia/Reperfusion Injury

Interferon-γ (IFN-γ) is a soluble cytokine that binds to the IFN-γ receptor and activates the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway, modulating various cell functions. The present study investigated the potential role of IFN-γ in ferroptosis after ischemia/reperfusion (I/R) injury. Focal cerebral ischemia was induced in mice using the middle cerebral artery occlusion (MCAO) model. This study evaluated neurological function, cerebral infarct volume, cerebral blood flow, neuronal apoptosis, oxidative stress, and ferroptosis. We first identified an increased protein level of IFN-γ after cerebral ischemia. Treatment with the IFN-γ inhibitor, Emapalumab, could significantly ameliorate neurological deficits, reduce infarct volume, and improve cerebral blood flow. In contrast, recombinant IFN-γ (r-IFN-γ) exacerbated these effects. In vivo experiments indicated that IFN-γ inhibition attenuated neuronal apoptosis by regulating apoptotic proteins, including Bax, Bcl-2, and Caspase 3. Moreover, IFN-γ inhibition reduced oxidative stress and ferroptosis by inhibiting the phosphorylation of STAT1 and the level of IRF1. Conversely, r-IFN-γ increased I/R-induced neuronal apoptosis, oxidative stress, and ferroptosis. JAK or STAT1 inhibition could counteract the detrimental effects of r-IFN-γ on cerebral ischemic injury. Our results indicate that r-IFN-γ aggravates cerebral ischemic injury via activation of the JAK/STAT1/IRF1 signaling pathway. The IFN-γ/JAK/STAT1/IRF1 signaling axis plays a crucial role in ferroptosis, suggesting that targeting this pathway may be a potential therapeutic strategy for ischemic stroke.