Abstract
BACKGROUND/OBJECTIVES: Cellular oxidative stress is crucial for GV stage oocyte vitrification quality. PI3K and the aquaporin family have been shown to facilitate various cellular processes related to redox homeostasis and energy balance; yet, the mechanisms underlying the involvement of aquaporin 7 (AQP7) in vitrified oocyte oxidative stress remain unclear. The purpose of the present investigation was to evaluate the role of AQP7 in vitrified oocytes and the mechanisms involved. METHODS: AQP7 inhibitors were employed to investigate the effect of AQP7 on oxidative stress in mouse-vitrified oocytes, whereas PI3K activators were harnessed to ascertain whether AQP7 serves as a functional molecule involved in this process. RESULTS: Our results indicate that AQP7 inhibition in vitrified oocytes results in a significant decrease in glutathione (GSH) levels associated with cellular oxidation and an elevation in H(2)O(2) levels. This was accompanied by exacerbated mitochondrial dysfunction, weakened cytoskeletal proteins, accelerated early apoptosis. Consequently, both survival and maturation rates were markedly reduced. Interestingly, PI3K/AKT activation increased AQP7 expression, restored abnormal mitochondrial distribution, as well as calcium homeostasis, and rescued the oocyte survival/maturation rate. CONCLUSIONS: Our results provide new insights indicating that PI3K/AKT/AQP7 decreases oxidative stress by regulating mitochondrial morphology, function, and distribution, thereby rescuing oocyte maturation in vitrification.