Early post-resuscitation administration of IMRCs attenuated cerebral injury following cardiac arrest, and this protective effect was possibly related to the suppression of ferroptosis via regulation of the SAT1/ALOX15/GPX4 signaling pathway.
Key Findings
Results
IMRC administration significantly decreased ferroptosis-related markers at multiple time points following cardiac arrest in a porcine model.
Ferroptosis-related markers decreased included ferrous iron (Fe2+), lipid reactive oxygen species (ROS), malondialdehyde (MDA), and 4-hydroxynonenal (4-HNE).
Reductions were observed at 24, 48, and 72 hours following cardiac arrest.
IMRCs concomitantly elevated glutathione (GSH) levels, a key antioxidant involved in ferroptosis resistance.
The model used male domestic white swine with experimentally induced cardiac arrest.
Results
IMRC administration mitigated cerebral injury and improved neurological function following cardiac arrest in swine.
Neurological function, cerebral injury, and ferroptosis-related indicators were systematically evaluated using a series of experimental assays.
IMRCs were derived from human embryonic stem cells (hESCs) and administered following cardiac arrest rather than as pretreatment.
This post-resuscitation administration approach was chosen given the unpredictable nature of cardiac arrest, distinguishing it from prior MSC pretreatment studies.
Results
In vivo IMRC administration downregulated SAT1 and ALOX15 expression while upregulating GPX4 levels in the porcine cardiac arrest model.
SAT1 (spermidine/spermine N1-acetyltransferase 1), ALOX15 (arachidonate 15-lipoxygenase), and GPX4 (glutathione peroxidase 4) are key regulators of ferroptosis.
GPX4 is a critical enzyme that protects cells against lipid peroxidation-induced ferroptosis; its upregulation by IMRCs suggests a protective mechanism.
The regulation of the SAT1/ALOX15/GPX4 signaling pathway was identified as a possible mechanism underlying IMRC-mediated neuroprotection.
Results
SAT1 overexpression in vitro promoted ALOX15 activation and suppressed GPX4 expression, thereby exacerbating hypoxia/reoxygenation-induced neuronal ferroptosis.
In vitro cardiac arrest-induced injury was simulated by subjecting HT22 cells and primary cultures of hippocampal neurons to hypoxia/reoxygenation (H/R).
SAT1 overexpression was achieved in HT22 cells via lentiviral transduction and in primary hippocampal neuron cultures via adeno-associated virus (AAV) transduction.
Cell viability and lactate dehydrogenase (LDH) release were among the assays used to evaluate ferroptosis.
SAT1 overexpression worsened H/R-induced neuronal ferroptosis by activating ALOX15 and suppressing GPX4.
Results
SAT1 overexpression partially attenuated the protective effects of IMRCs against hypoxia/reoxygenation-induced ferroptosis in vitro.
This finding suggests that IMRCs exert their neuroprotective effects at least in part through suppression of the SAT1 pathway.
The partial—rather than complete—attenuation indicates that IMRCs may also engage additional protective mechanisms beyond the SAT1/ALOX15/GPX4 axis.
Experiments were conducted in both HT22 cells and primary cultures of hippocampal neurons.
Background
IMRCs derived from human embryonic stem cells were used as the therapeutic agent, distinguishing this study from prior mesenchymal stem cell pretreatment approaches.
Prior emerging evidence indicated that MSC pretreatment exerted protective effects against cardiac and cerebral injuries in porcine CA models.
IMRCs (immunity-and-matrix-regulatory cells) were administered post-cardiac arrest rather than as pretreatment, making the approach more clinically translatable.
The study used a porcine model, which is considered more translationally relevant to human cardiac arrest physiology than rodent models.
What This Means
This research suggests that a specialized type of stem cell therapy—using cells called IMRCs (immunity-and-matrix-regulatory cells) derived from human embryonic stem cells—can reduce brain damage after cardiac arrest in pigs. The study found that giving IMRCs after resuscitation lowered levels of harmful molecules associated with a type of cell death called ferroptosis, which involves iron-driven oxidative damage to cells. At the same time, IMRCs raised levels of protective antioxidants like glutathione and improved neurological function in the animals over a 72-hour observation period.
The researchers also identified a specific molecular pathway—involving proteins called SAT1, ALOX15, and GPX4—through which IMRCs appear to work. In laboratory experiments using brain cells subjected to simulated cardiac arrest conditions, artificially increasing SAT1 levels made ferroptosis worse and partially canceled out the protective benefits of IMRCs, supporting the idea that IMRCs work in part by keeping this pathway in check. This is notable because ferroptosis is an increasingly recognized form of cell death in brain injury, and targeting it represents a relatively new therapeutic direction.
This research matters because brain injury after cardiac arrest remains one of the leading causes of death and disability in survivors, and there are currently no well-established treatments to prevent it. The use of post-resuscitation cell therapy—rather than pretreatment—is a more practical approach since cardiac arrests cannot be predicted. While this work was conducted in animals and needs further validation before any clinical application, it points to IMRCs and the ferroptosis pathway as potentially promising targets for future therapies aimed at protecting the brain after cardiac arrest.
He L, Li L, Xu J, Chen Q, Yang H, Zhu J, et al.. (2026). IMRCs Alleviate Post-resuscitation Cerebral Injury Possibly by Inhibiting Ferroptosis in a Porcine Model of Cardiac Arrest.. Neurochemical research. https://doi.org/10.1007/s11064-026-04918-0