hESC-MSC-EVs attenuate post-cardiac arrest brain injury by inhibiting cGAS/STING-mediated neuronal pyroptosis

Abstract

Cardiac arrest-induced brain injury significantly affects patient prognosis, yet effective therapeutic strategies remain lacking in clinical practice. In recent years, mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) have garnered considerable attention for their notable neuroprotective potential. However, studies in cardiac arrest models remain relatively limited. This study aimed to investigate the protective effects and underlying mechanisms of human embryonic stem cell-derived mesenchymal stem cell extracellular vesicles (hESC-MSC-EVs) against brain injury following cardiac arrest/resuscitation (CA/CPR). In vivo, a rat model of cardiac arrest was established by asphyxia, and hESC-MSC-EVs were administered intravenously after resuscitation. In vitro, HT22 cells were subjected to oxygen-glucose deprivation/reoxygenation (OGD/R). The results demonstrated that hESC-MSC-EVs significantly improved neurological function at 24 h post-resuscitation, reduced serum levels of NSE and S100B, alleviated pathological damage, and inhibited apoptosis in the hippocampal CA1 region at 7 days after resuscitation. In vitro experiments further confirmed that hESC-MSC-EVs increased HT22 cell viability, reduced reactive oxygen species levels, and suppressed apoptosis. Further mechanistic investigation revealed that hESC-MSC-EVs significantly attenuated pyroptosis in HT22 cells and rat hippocampal neurons, and suppressed the expression of cGAS/STING pathway-related proteins. Activation of the cGAS/STING pathway exacerbated OGD/R-induced HT22 cell injury and CA/CPR-induced brain injury, whereas hESC-MSC-EVs intervention effectively reversed these effects. Mechanistically, miR-181a-5p was identified to target and inhibit Cgas and transfection with miR-181a-5p mimics downregulated the cGAS/STING signaling pathway and alleviated pyroptosis in HT22 cells. Collectively, hESC-MSC-EVs ameliorate brain injury following CA/CPR by inhibiting cGAS/STING-mediated neuronal pyroptosis, offering novel potential therapeutic targets and strategies for clinical management.