Improving vitrification efficiency of human in vitro matured oocytes by the addition of LEA proteins

Vitrification cryopreservation of oocytes is an enabling technology for assisted reproductive technology. However, many factors in the vitrification process, such as the toxicity of cryoprotectant, osmotic stress, ice crystal formation during rewarming, will cause fatal damage to oocytes, thus affecting the embryo developmental potential and subsequent clinical outcomes. Therefore, oocyte vitrification still faces significant challenges. Recent studies have shown that LEA protein has the potential to improve oocyte cryopreservation, while the molecular mechanism by which it exerts protective effects is still unclear. Therefore, we have systematically investigated the effects of LEA proteins on the vitrification cryopreservation and their molecular mechanisms. Results revealed that the proteins improved the developmental potential of human oocytes following cryopreservation, mostly by downregulating FOS genes and reducing oxidative stress. Moreover, the synergistic cryoprotection of LEA proteins by inhibiting the formation of ice crystals was given full play. This study provides a new strategy for high-quality cryopreservation of human oocytes.