Sperm insulin-like growth factor 2 protein levels: implications for early embryo development

Area of Science:

• Reproductive Biology
• Developmental Biology
• Genetics

Background:

• Sperm-derived factors play crucial roles in early embryonic development.
• Insulin-like growth factor 2 (IGF2) is implicated in cellular growth and differentiation.
• The specific contribution of sperm IGF2 to human embryogenesis and assisted reproductive technology (ART) outcomes remains unclear.

Purpose of the Study:

• To investigate the role of sperm-derived insulin-like growth factor 2 (IGF2) in early human embryo development.
• To determine the association between sperm IGF2 levels and embryo morphokinetics during ART.
• To explore the potential influence of sperm IGF2 on ART success rates.

Main Methods:

• Quantified sperm IGF2 levels in 27 infertile couples undergoing ART using ELISA.
• Assessed correlation between sperm IGF2 and embryo morphokinetics via time-lapse imaging.
• Investigated underlying mechanisms using recombinant IGF2 in murine parthenote cultures and transcriptome analysis.

Main Results:

• Sperm IGF2 levels correlated with sperm recovery and early pronuclear formation timing, suggesting a role in initial embryogenesis.
• No significant correlation was found with later embryo development stages or ART outcomes (pregnancy, live birth).
• IGF2 addition to parthenotes enriched pathways crucial for pronuclear formation, indicating a mechanistic link.

Conclusions:

• Sperm-delivered IGF2 appears involved in early post-fertilization events.
• Its effect on later embryonic development and ART outcomes seems limited.
• Further research is warranted to explore IGF2's diagnostic and therapeutic potential in male-factor infertility.