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Background Neonatal hypoxic-ischemic brain injury (HIBI) results from disruptions to blood supply and oxygen in the perinatal brain. The goal of this study was to measure brain sterol metabolites and plasma oxysterols after injury in a neonatal HIBI mouse model to assess for potential therapeutic targets in the brain biochemistry as well as potential circulating diagnostic biomarkers. Methods Postnatal day 9 CD1-IGS mouse pups were randomized to HIBI induced by carotid artery ligation followed by 30 minutes at 8% oxygen or to sham surgery and normoxia. Brain tissue was collected for sterol analysis by liquid chromatography with tandem mass spectrometry (LC–MS/MS). Plasma was collected for oxysterol analysis by LC–MS/MS. Results There were minimal changes in brain sterol concentrations in the first 72 hours after HIBI. In severely injured brains, there was a significant increase in desmosterol, 7-DHC, 8-DHC, and cholesterol 24 hours after injury in the ipsilateral tissue. Lanosterol, 24-dehydrolathosterol, and 14-dehydrozymostenol decreased in plasma 24 hours after injury. Severe neonatal HIBI was associated with increased cholesterol and sterol precursors in the cortex at 24 hours after injury. Conclusions Differences in plasma oxysterols were seen at 24 hours but were not present at 30 minutes after injury, suggesting that these sterol intermediates would be of little value as early diagnostic biomarkers. [ABSTRACT FROM AUTHOR]

Ferroptosis is a type of programmed cell death caused by phospholipid peroxidation that has been implicated as a mechanism in several diseases resulting from ischemic-reperfusion injury. Most recently, ferroptosis has been identified as a possible key injury mechanism in neonatal hypoxic-ischemic brain injury (HIBI). This review summarizes the current literature regarding the different ferroptotic pathways, how they may be activated after neonatal HIBI, and which current or investigative interventions may attenuate ferroptotic cell death associated with neonatal HIBI. [ABSTRACT FROM AUTHOR]

Introduction: Neonatal hypoxic-ischemic brain injury (HIBI) results in significant morbidity and mortality despite current available therapies. Seeking a potential supplemental therapy for HIBI, we investigated the neuroprotective effects of extracellular vesicles derived from neural stem cells (NSC-EVs) and hypoxia-preconditioned brain cells (brain-EVs). Methods: HIBI was induced in postnatal day 9 mice by carotid ligation followed by hypoxia. Following injury, NSC-EVs, brain-EVs, or saline were administered intranasally. Brains were assessed for infarct size, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and caspase-3 expression. Additionally, brain-EV microRNA (miRNA) contents were analyzed by miRNA sequencing. Results: Both EV treated groups showed decreased infarct size (brain-EVs p = 0.004 and NSC-EVs p = 0.052), and although NSC-EV administration resulted in significantly fewer TUNEL+ cells (p = 0.0098), there was no change in caspase-3 expression after NSC-EV administration, suggesting a caspase-3-independent mechanism. Brain-EVs resulted in a nonsignificant decrease in TUNEL+ cells (p = 0.167) but significant decreases in caspase expression (cleaved p = 0.015 and intact p = 0.026). Brain-EVs consistently expressed several miRNAs, including two which have been shown to be downregulated after HIBI: miR-342-3p and miR-330-3p. Conclusion: Understanding the regenerative effects and contents of NSC-EVs and brain-EVs could allow for the development of targeted EV-based therapies that could reduce morbidity and mortality for neonates affected by HIBI. [ABSTRACT FROM AUTHOR]

Hypoxic-ischemic brain injury (HIBI) leads to depletion of ATP, mitochondrial dysfunction, and enhanced oxidant formation. Measurement of acylcarnitines may provide insight into mitochondrial dysfunction. Plasma acylcarnitine levels are altered in neonates after an HIBI, but individual acylcarnitine levels in the brain have not been evaluated. Additionally, it is unknown if plasma acylcarnitines reflect brain acylcarnitine changes. In this study, postnatal day 9 CD1 mouse pups were randomized to HIBI induced by carotid artery ligation, followed by 30 min at 8% oxygen, or to sham surgery and normoxia, with subgroups for tissue collection at 30 min, 24 h, or 72 h after injury (12 animals/group). Plasma, liver, muscle, and brain (dissected into the cortex, cerebellum, and striatum/thalamus) tissues were collected for acylcarnitine analysis by LC-MS. At 30 min after HIBI, acylcarnitine levels were significantly increased, but the differences resolved by 24 h. Palmitoylcarnitine was increased in the cortex, muscle, and plasma, and stearoylcarnitine in the cortex, striatum/thalamus, and cerebellum. Other acylcarnitines were elevated only in the muscle and plasma. In conclusion, although plasma acylcarnitine results in this study mimic those seen previously in humans, our data suggest that the plasma acylcarnitine profile was more reflective of muscle changes than brain changes. Acylcarnitine metabolism may be a target for therapeutic intervention after neonatal HIBI, though the lack of change after 30 min suggests a limited therapeutic window. [ABSTRACT FROM AUTHOR]