[Alda-1 alleviates brain injury after cardiopulmonary resuscitation by regulating acyl-CoA synthetase long-chain family member 4/glutathione peroxidase 4 pathway-mediated ferroptosis in swine]

Abstract

Objective: To investigate whether the acetaldehyde dehydrogenase 2 specific activator, Alda-1, can alleviate brain injury after cardiopulmonary resuscitation (CPR) by inhibiting cell ferroptosis mediated by acyl-CoA synthetase long-chain family member 4/glutathione peroxidase 4 (ACSL4/GPx4) pathway in swine.

Methods: Twenty-two conventional healthy male white swine were divided into Sham group (n = 6), CPR model group (n = 8), and Alda-1 intervention group (CPR+Alda-1 group, n = 8) using a random number table. The swine model of CPR was reproduced by 8 minutes of cardiac arrest induced by ventricular fibrillation through electrical stimulation in the right ventricle followed by 8 minutes of CPR. The Sham group only experienced general preparation. A dose of 0.88 mg/kg of Alda-1 was intravenously injected at 5 minutes after resuscitation in the CPR+Alda-1 group. The same volume of saline was infused in the Sham and CPR model groups. Blood samples were collected from the femoral vein before modeling and 1, 2, 4, 24 hours after resuscitation, and the serum levels of neuron specific enolase (NSE) and S100 β protein were determined by enzyme-linked immunosorbent assay (ELISA). At 24 hours after resuscitation, the status of neurologic function was evaluated by neurological deficit score (NDS). Thereafter, the animals were sacrificed, and brain cortex was harvested to measure iron deposition by Prussian blue staining, malondialdehyde (MDA) and glutathione (GSH) contents by colorimetry, and ACSL4 and GPx4 protein expressions by Western blotting.

Results: Compared with the Sham group, the serum levels of NSE and S100β after resuscitation were gradually increased over time, and the NDS score was significantly increased, brain cortical iron deposition and MDA content were significantly increased, GSH content and GPx4 protein expression in brain cortical were significantly decreased, and ACSL4 protein expression was significantly increased at 24 hours after resuscitation in the CPR model and CPR+Alda-1 groups, which indicated that cell ferroptosis occurred in the brain cortex, and the ACSL4/GPx4 pathway participated in this process of cell ferroptosis. Compared with the CPR model group, the serum levels of NSE and S100 β starting 2 hours after resuscitation were significantly decreased in the CPR+Alda-1 group [NSE (μg/L): 24.1±2.4 vs. 28.2±2.1, S100 β (ng/L): 2 279±169 vs. 2 620±241, both P < 0.05]; at 24 hours after resuscitation, the NDS score and brain cortical iron deposition and MDA content were significantly decreased [NDS score: 120±44 vs. 207±68, iron deposition: (2.61±0.36)% vs. (6.31±1.66)%, MDA (μmol/g): 2.93±0.30 vs. 3.68±0.29, all P < 0.05], brain cortical GSH content and GPx4 expression in brain cortical was significantly increased [GSH (mg/g): 4.59±0.63 vs. 3.51±0.56, GPx4 protein (GPx4/GAPDH): 0.54±0.14 vs. 0.21±0.08, both P < 0.05], and ACSL4 protein expression was significantly decreased (ACSL4/GAPDH: 0.46±0.08 vs. 0.85±0.13, P < 0.05), which indicated that Alda-1 might alleviate brain cortical cell ferroptosis through regulating ACSL4/GPx4 pathway.

Conclusions: Alda-1 can reduce brain injury after CPR in swine, which may be related to the inhibition of ACSL4/GPx4 pathway mediated ferroptosis.