The PI3K/Akt/mTOR Signaling Pathway Plays a Role in Regulating Autophagy in Mouse Oocytes During Vitrification-Warming and In Vitro Maturation

BACKGROUND: It has been shown that vitrified-warmed oocytes exhibit autophagic activation. However, its regulatory molecular mechanism of autophagy needs to be clarified. OBJECTIVE: To determine the role of signaling pathway of PI3K/Akt/mTOR in the regulation of autophagy in oocytes during vitrification-warming and IVM. MATERIALS AND METHODS: Oocytes from mice were vitrified-warmed and IVM. The expressions of LC3-II, Beclin-1, PI3K, Akt, and mTOR protein were determined. Moreover, the ATP level, viability of vitrified-warmed oocytes, and their developmental potential were measured. RESULTS: At 6 h of incubation of warmed oocytes, the LC3-II and Beclin1 expressions were markedly up-regulated, whereas PI3K, Akt, and mTOR proteins expressions were significantly down-regulated. In addition, autophagy inhibition significantly decreased ATP level, viability of oocytes, and their developmental potential. CONCLUSION: Autophagy plays a protective role in the oocytes during vitrification-warming and IVM. The PI3K/Akt/mTOR pathway participated in regulating autophagy activity in oocyte during vitrification-warming and IVM.