Maternal age is associated with apoptotic gene abundance patterns in blastocoel fluid-conditioned media from euploid embryos: a pilot study.

PURPOSE

This retrospective study measured global gene abundance using RNASeq of blastocoel fluid-conditioned media from euploid ICSI-generated embryos to identify genes and signaling pathways associated with maternal age.

METHODS

Blastocoel fluid-conditioned media was obtained following trophectoderm biopsy of ICSI-generated day-5 blastocysts. Media for RNASeq were from 24 euploid blastocysts (9 from patients aged 35 or older). Transcriptome analysis identified differentially expressed genes when comparing media from patients of advanced maternal age to those younger than 35. Further gene abundance analysis on genes and pathways identified from the RNASeq analysis was conducted with another group of media samples using RT-qPCR.

RESULTS

Twenty-five protein encoding genes identified in the RNASeq study were differentially expressed when comparing blastocoel fluid-conditioned media associated with patients of advanced maternal age to media associated with patients under the age of 35. Genes encoding the proteins SHARPIN and BCL2L12 showed a statistically significant increase (p < 0.05) in abundance in patients of advanced maternal age. Abundance analysis using RT-qPCR in additional media samples revealed elevated SHARPIN abundance in media associated with successful implantation in patients under 35 alongside a decrease in CASP8 abundance. This abundance pattern was the opposite in media associated with successful implantation in patients of advanced maternal age.

CONCLUSIONS

This study uncovered differential apoptotic gene abundance associated with maternal age by assessing blastocoel fluid-conditioned media from euploid blastocysts. These unique abundance patterns may provide insight into the regulation of apoptosis in embryos from women of advanced maternal age, and how this signaling pathway may impact implantation outcomes.