Activated PI3K/AKT Signaling Pathway Associates with Oxidative Stress and Impaired Developmental Potential of Vitrified-Thawed Oocytes

It was suggested that the compromised developmental potential of vitrified-thawed oocytes was due to the oxidative stress occurred during the process. PI3K/AKT signaling pathway is important in response to stress. The present study aimed to investigate the role of PI3K/AKT played in oocyte vitrification and thawing. The results revealed that the fertilization rate, cleavage rate, as well as the blastocyst formation rate were significantly lower in the vitrified-thawed oocytes than that of the control counterparts [63.81 ± 7.19 vs. 82.00 ± 4.21% (P < 0.05), 58.89 ± 8.39 vs. 78.92 ± 2.78% (P < 0.05), and 59.37 ± 7.03 vs. 74.56 ± 5.06% (P < 0.05), respectively]. Significantly increased reactive oxygen species (ROS) level (P < 0.01), decreased mitochondrial membrane potential (P < 0.01), and declined SIRT3 expression level (P < 0.01) were observed in vitrified-thawed oocytes compared with that of the fresh group. In addition, enhanced PIK3CA was quantified (P < 0.05), and the protein expression levels of PIK3CA (P < 0.05) and P-AKT (P < 0.01) were increased in vitrified-thawed oocytes compared to the fresh ones. Also, decreased SIRT3 level was observed after vitrification/thawing (P < 0.01). In conclusion, our data demonstrated a link between activated PI3K/AKT signaling pathway in response to oxidative stress and compromised developmental potential in vitrified-thawed oocytes.