Female control mice displayed improved recovery of cardiac mitochondrial respiratory function and higher ATP levels versus males in response to acute oxygen deprivation, independent of Akt signaling.
Does female sex improve mitochondrial respiratory function and ATP levels in response to acute oxygen deprivation in mice?
Female mouse hearts exhibit a metabolic gene switch that enhances mitochondrial bioenergetic capacity and tolerance to oxygen deprivation, independent of Akt signaling.
The mechanisms underlying increased cardioprotection in younger female mice are unclear. We hypothesized that serine-threonine protein kinase (protein kinase B; Akt) triggers a metabolic gene switch (decreased fatty acids, increased glucose) in female hearts to enhance mitochondrial bioenergetic capacity, conferring protection against oxidative stress. Here, we employed male and female control (db/+) and obese (db/db) mice. We found diminished transcript levels of peroxisome proliferator-activated receptor-alpha, muscle-type carnitine palmitoyltransferase 1 and pyruvate dehydrogenase kinase 4 in female control hearts versus male hearts. Moreover, females displayed improved recovery of cardiac mitochondrial respiratory function and higher ATP levels versus males in response to acute oxygen deprivation. All these changes were reversed in female db/db hearts. However, we found no significant gender-based differences in levels of Akt, suggesting that Akt-independent signaling mechanisms are responsible for the resilient mitochondrial phenotype observed in female mouse hearts. As glucose is a more energetically efficient fuel substrate when oxygen is limiting, this gene program may be a crucial component that enhances tolerance to oxygen deprivation in female hearts.
Essop et al. (Mon,) conducted a other in Oxidative stress. Female sex vs. Male sex was evaluated on Cardiac mitochondrial respiratory function and ATP levels in response to acute oxygen deprivation. Female control mice displayed improved recovery of cardiac mitochondrial respiratory function and higher ATP levels versus males in response to acute oxygen deprivation, independent of Akt signaling.