Antioxidant supplementation of mouse embryo culture or vitrification media support more in-vivo-like gene expression post-transfer.

Research Question: What is the effect on mouse fetal gene expression of combined antioxidants (acetyl-L-carnitine, N-acetyl-L-cysteine and alpha-lipoic acid; A3) when used in culture media and vitrification/warming solutions?

Design: A laboratory-based analysis of an animal model. Embryo transfers were conducted on in-vivo-flushed blastocysts, or blastocysts cultured or vitrified with and without A3. Transcriptional profiles of E14.5 fetal liver and placental tissue in all groups were quantified using RNA-Seq and functional analyses (gene ontology [GO] biological processes and Kyoto Encyclopedia of Genes and Genomes [KEGG] pathway analysis).

Results: Both in-vitro culture in the presence of 20% oxygen and vitrification of blastocysts significantly perturbed fetal liver and placental gene expression. Notably, supplementation of in-vitro culture media or vitrification/warming solutions with A3 reduced the number of differentially expressed genes (DEG) and biological processes altered, establishing a more in-vivo-like gene expression profile, particularly within the E14.5 placenta. Specifically, A3 supplementation significantly reduced the expression of genes associated with pre-eclampsia and intrauterine growth restriction, along with genes involved in metabolism, cell senescence and cancer associated pathways. However, despite these improvements, several biological processes remained over-represented following both in-vitro culture and vitrification, even in the presence of A3.

Conclusion: Both in-vitro culture in the presence of 20% oxygen and vitrification of blastocysts significantly perturbed fetal liver and placental gene expression, with the number of DEG greater following vitrification. Supplementation with A3 reduced the number of DEG and biological processes altered, establishing a more in-vivo-like gene expression profile, particularly in the placenta. Notably, A3 supplementation of in-vitro culture media significantly reduced the expression of genes associated with pre-eclampsia and intrauterine growth restriction.