Mechanism of Sirtuin1-Mediated Deacetylation of p65-Mediated Ferroptosis of Hippocampal Neurons in Cerebral Injury after Cardiopulmonary Resuscitation in Rats.

Objective: Post-resuscitation brain injury is a common sequela after cardiac arrest (CA). Increasing sirtuin1 (SIRT1) has been involved in neuroprotection in oxygen-glucose deprivation (OGD) neurons, and we investigated its mechanism in post-cardiopulmonary resuscitation (CPR) rat brain injury by mediating p65 deacetylation modification to mediate hippocampal neuronal ferroptosis.

Methods: Sprague-Dawley rat CA/CPR model was established and treated with Ad-SIRT1 and Ad-GFP adenovirus vectors, or Erastin. Rat postoperative neurological function, and cognitive and learning abilities were assessed by neurological deficit score and Morris water maze test. Hippocampal neuronal pathological changes and injury were evaluated by H&E and TUNEL staining. Serum brain injury biomarkers and hippocampal inflammatory factors and SIRT1 mRNA levels were determined by ELISA and RT-qPCR. OGD/reoxygenation (OGD/R) rat hippocampal neuron (H19-7) model was established. Cell viability and injury, nuclear factor-kappa B (NF-κB) p65 localization, iron content, and levels of glutathione, malondialdehyde, reactive oxygen species, SIRT1, Ac NF-κB p65 (Lys310), NF-κB p65, ACSL4, glutathione peroxidase 4 and SLC7A11 were measured.

Results: In CA/CPR rats, SIRT1 was down-regulated, and SIRT1 overexpression alleviated cerebral injury. SIRT1 overexpression inhibited OGD/R-induced H19-7 cell ferroptosis to ameliorate cell injury, and inactivated the NF-κB pathway by reducing p65 acetylation to hinder its entry into the nucleus. Inactivating the NF-κB pathway reduced OGD/R-induced ferroptosis and alleviated cell injury. SIRT1 alleviated cerebral injury by mediating p65 deacetylation to inhibit hippocampal neuronal ferroptosis mediated by the NF-κB pathway.

Conclusions: SIRT1 inhibited the NF-κB signaling pathway-mediated hippocampal neuronal ferroptosis by mediating p65 deacetylation modification, thereby alleviating brain injury in CA/CPR rats.