60 Investigating placental protein changes associated with Assisted Reproductive Technologies in a mouse model

Abstract Pregnancies utilizing Assisted Reproductive Technologies (ART) are associated with several complications including an increased risk of preeclampsia, placental abruption, and morbidly adherent placentas. Our work along with others has shown that placentas from mice conceived by in vitro fertilization (IVF) display overgrowth, impaired blood vessel development, altered gene expression and DNA methylation. These changes are associated with impaired fetal growth. We sought to identify the placental protein differences with IVF to inform potential interventions for improving ART procedures. Placental protein differences among IVF and spontaneously-conceived mouse concepti were analyzed in a sex-specific manner (n = 4-5 placentas/sex/experimental group/timepoint) by data-independent acquisition mass spectrometry at five timepoints covering shortly after placental formation through term (E11.5, 12.5, 14.5, 16.5, and 18.5). Peptides below 1% FDR were included, and statistical analysis was performed using Two-way ANOVA and Tukey HSD post hoc tests, and adjustment for multiple hypothesis testing. We observed normal, dynamic abundance changes for placental proteins over development. IVF induces an overall reduction in the abundance of several placental proteins at the earliest timepoint, E11.5. Several of the identified affected proteins are known to be important for placenta development and epigenetic regulation. Intriguingly, we observed most placental protein changes were observed among the female concepti but not the male concepti. To our knowledge, this is the first proteomic analysis of mouse placentas at multiple timepoints along gestation. We are currently conducting spatial transcriptomics experiments to determine if protein changes are associated with specific placental compartments.