Sex‐dependent mitochondrial respiratory impairment and oxidative stress in a rat model of neonatal hypoxic‐ischemic encephalopathy

作者：Tyler G. Demarest, Rosemary A. Schuh, Jaylyn Waddell, Mary C. McKenna, Gary Fiskum · 发表于：Journal of Neurochemistry · 年份：2016 · DOI：10.1111/jnc.13590 · 被引用次数：92 · 研究领域：Neonatal and fetal brain pathology、Mitochondrial Function and Pathology、Traumatic Brain Injury and Neurovascular Disturbances

Increased male susceptibility to long-term cognitive deficits is well described in clinical and experimental studies of neonatal hypoxic-ischemic encephalopathy. While cell death signaling pathways are known to be sexually dimorphic, a sex-dependent pathophysiological mechanism preceding the majority of secondary cell death has yet to be described. Mitochondrial dysfunction contributes to cell death following cerebral hypoxic-ischemia (HI). Several lines of evidence suggest that there are sex differences in the mitochondrial metabolism of adult mammals. Therefore, this study tested the hypothesis that brain mitochondrial respiratory impairment and associated oxidative stress is more severe in males than females following HI. Maximal brain mitochondrial respiration during oxidative phosphorylation was two-fold more impaired in males following HI. The endogenous antioxidant glutathione was 30% higher in the brain of sham females compared to males. Females also exhibited increased glutathione peroxidase (GPx) activity following HI injury. Conversely, males displayed a reduction in mitochondrial GPx4 protein levels and mitochondrial GPx activity. Moreover, a 3-4-fold increase in oxidative protein carbonylation was observed in the cortex, perirhinal cortex, and hippocampus of injured males, but not females. These data provide the first evidence for sex-dependent mitochondrial respiratory dysfunction and oxidative damage, which may contribute to the relative male susceptibility to ...