Conservation at the uterine-placental interface

Abstract

The hemochorial placentation site is characterized by a dynamic interplay between trophoblast cells and maternal cells. These cells cooperate to establish an interface required for nutrient delivery to promote fetal growth. In the human, trophoblast cells penetrate deep into the uterus. This is not a consistent feature of hemochorial placentation and has hindered the establishment of suitable animal models. The rat represents an intriguing model for investigating hemochorial placentation with deep trophoblast cell invasion. In this study, we used single cell RNA sequencing to characterize the transcriptome of the invasive trophoblast cell lineage, as well as other cell populations within the rat uterine-placental interface during early (gestation day, gd, 15.5) and late (gd 19.5) stages of intrauterine trophoblast cell invasion. We identified a robust set of transcripts that define invasive trophoblast cells, as well as transcripts that distinguished endothelial, smooth muscle, natural killer, and macrophage cells. Invasive trophoblast, immune, and endothelial cell populations exhibited distinct spatial relationships within the uterine-placental interface. Furthermore, the maturation stage of invasive trophoblast cell development could be determined by assessing gestation-stage dependent changes in transcript expression. Finally, and most importantly, expression of a prominent subset of rat invasive trophoblast cell transcripts is conserved in the invasive extravillous trophoblast cell lineage of the human placenta. These findings provide foundational data to identify and interrogate key conserved regulatory mechanisms essential for development and function of an important compartment within the hemochorial placentation site that is essential for a healthy pregnancy.

CITED2 is a Conserved Regulator of the Uterine-Placental Interface

“…The uterine-placental interface from gd 18.5 was selected to obtain sufficient number of invasive trophoblast cells for analysis. Uniform manifold approximation and projection (UMAP) profiles of the uterine-placental interface were similar to previously published UMAP profiles for the rat uterine-placental interface (40). Cited2 expression was enriched in the invasive trophoblast cell cluster (Fig.…”

“…Uterine-placental interface tissues were dissected from gd 18.5 placentation sites (61), minced into small pieces, and enzymatically digested into a cell suspension for scRNA-seq as previously described (40, 63). Samples were then processed using Chromium Single Cell RNA-seq (10X Genomics) and libraries prepared using the Chromium Single Cell 3” kit (10x Genomics).…”

Conditionally mutant animal model for investigating the invasive trophoblast cell lineage

“…1B). At gd 19.5, 99.7 percent of invasive trophoblast cells located within the uterineplacental interface express Prl7b1 (Scott et al, 2022). snATAC-seq revealed that the regulatory region of Prl7b1 is accessible in the invasive trophoblast cell cluster (Fig.…”

“…We recently performed single cell RNA-sequencing (scRNA-seq) and single nucleus assay for transposase-accessible chromatin using sequencing (snATAC-seq) for the rat uterine-placental interface from gestation day (gd) 15.5 and 19.5 (Scott et al, 2022;Vu et al, 2023). Prl7b1 was abundantly and specifically expressed within invasive trophoblast cells (Fig.…”

“…It is evident that some regulatory pathways controlling invasive trophoblast cells also contribute to earlier phases of placentation or more broadly to embryogenesis (Hemberger et al, 2020;Scott et al, 2022;Vu et al, 2023). Lentiviral strategies targeted to trophectoderm of the blastocyst have been developed to manipulate gene expression in mouse and rat Development • Accepted manuscript trophoblast cell lineages and address some of these issues (Georgiades et al, 2007;Okada et al, 2007;Lee et al, 2009).…”