Relationship of Early Embryonic Development In Vitro Fertilization With Sperm Zinc Homeostasis and Seminal Plasma Antioxidation

Abstract

The study aims to explore the sperm parameters that affect early embryo development in in vitro fertilization (IVF) and to study their relationship with sperm zinc homeostasis and seminal plasma antioxidation. The semen samples were incubated at 37°C for 1, 2, 3, and 4 h, and the sperm progressive motility (PR) was analyzed. We found that the sperm PR significantly decreased after 3 h of incubation (p < 0.01) and further decreased after 4 h (p < 0.001). The correlation analysis showed that sperm PR was significant positively correlated with transferable embryo rate (r = 0.155, p = 0.026) and blastocyst formation rate (r = 0.140, p = 0.044) after incubation for 4 h, while its decline rate was significant negatively correlated with transferable embryo rate (r = −0.151, p = 0.030) and blastocyst formation rate (r = −0.220, p = 0.002). Additionally, the ELISA assay indicated that patients with PR > 32% and decline rate < 30% had significantly higher levels of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) in the seminal plasma compared to patients with PR < 32% and decline rate > 30% (p < 0.05), while malondialdehyde (MDA) levels were significantly lower (p < 0.05). The results of the zinc fluorescence probe showed that the level of free zinc ion in sperm in the high motility and low decline rate group was significantly higher than that in the low motility and high decline rate group (p < 0.05). The quantitative real-time polymerase chain reaction (qRT-PCR) and immunofluorescence results showed that the group with high motility and low decline rate had significantly higher relative expression levels of G protein-coupled receptor 39 (GPR39), anoctamin 1 (ANO1), and zinc transporter protein 13 (ZIP13) mRNA (p < 0.05). In conclusion, patients with low PR and high PR decline rate after 4 h of incubation had poor early embryo development results in IVF. This may be through the reduction of zinc homeostasis-associated protein expression to accelerate the oxidative stress process, thereby reducing sperm quality and ultimately affecting embryonic development.