Spermidine Supplementation Effectively Improves the Quality of Mouse Oocytes After Vitrification Freezing.

The cryopreservation of oocytes through vitrification is imperative for the conservation of livestock germplasm resources. However, as oocytes exhibit significant oxidative stress and organelle damage following vitrification freezing, it is crucial to optimise the vitrification conditions to mitigate the deleterious effects of freezing. In this study, we demonstrated that spermidine has been showed to enhance oocyte survival after vitrification freezing (92% ± 4% vs. 82% ± 3%, p < 0.01) and blastocyst formation after freezing for in vitro fertilisation (14.86% ± 7% vs. 6% ± 3, p < 0.05). Spermidine supplementation rescued 47.3% of dysregulated pathways, including ovarian steroidogenesis, and restored normal expression levels in 43.3% of aberrantly expressed genes. Subsequent studies elucidated that spermidine effectively rescued mitochondrial dysfunction after vitrification, alleviated oxidative stress damage, and regulated intracellular calcium homeostasis. Consequently, we concluded that the addition of spermidine during vitrification freezing is an effective method to protect oocytes from freezing damage.