Mesenchymal stem cell-derived exosomes overexpressing SRC-3 protect mice from cerebral ischemia by inhibiting ferroptosis

Background: The treatment for cerebral ischemia remains limited, and new therapeutic strategies are urgently needed. Exosome has shown great promise for the treatment of cerebral ischemia. Steroid receptor coactivator-3 (SRC-3) was reported to be involved in neurological performances. In this study, we aimed to investigate the protective effects of mesenchymal stem cell (MSC)-derived exosomes overexpressing SRC-3 on cerebral ischemia in mice. Methods: The mice were treated with an intracerebroventricular injection of GFP-overexpressed exosomes (GFPexo) and SRC-3-overexpressed exosomes (SRC3-exo) in a middle cerebral artery occlusion (MCAO) model of cerebral ischemia. Results: The results showed that SRC3-exo treatment significantly inhibited lipid peroxidation and ferroptosis of the neurons subjected to oxygen-glucose deprivation. It further suppressed the activation of microglia and astrocytes, and decreased the production of pro-inflammatory cytokines in the brains of MCAO mice. Furthermore, SRC3-exo treatment reduced the water content of brain tissue and infarct size, which alleviated the neurological damage and improved neurological performances in the MCAO mice. Conclusions: Our results suggest that MSC-derived exosomes expressing SRC3 can be a therapeutic strategy for cerebral ischemia by inhibiting ferroptosis.