# Regulation of Invasive Trophoblast Cell Lineage Development

> **NIH NIH R00** · CHILDREN'S MERCY HOSP (KANSAS CITY, MO) · 2024 · $241,882

## Abstract

PROJECT SUMMARY / ABSTRACT
Uterine vascular remodeling occurs during gestation to meet increasing fetal nutrient demands. This 
remodeling includes modification of the uterine spiral arteries into low resistance vessels for supplying blood to 
the fetus. Central to uterine spiral artery remodeling are invasive trophoblast cells, known in the human as 
extravillous trophoblast (EVT). Impaired EVT development leads to suboptimal fetal conditions and adverse 
pregnancy outcomes including pregnancy loss, preeclampsia, intrauterine growth restriction, and preterm birth. 
We identified a critical and conserved regulator of EVT lineage development, Achaete-Scute Family Basic 
Helix-Loop-Helix Transcription Factor 2 (ASCL2). Depletion of ASCL2 in human trophoblast stem (hTS) cells
inhibits EVT formation. Similarly, global depletion of ASCL2 in vivo disrupts placental development and causes 
embryonic lethality in the rat. However, the molecular mechanisms by which ASCL2 directs EVT lineage 
development are unknown. Our established hTS cell lines and protocols for generating mutant rat models will 
allow us to directly test our central hypothesis that ASCL2 controls EVT lineage development during 
placentation. To investigate higher order actions of ASCL2 on the epigenomic landscape of the EVT cell 
lineage, we will identify how ASCL2 depletion alters DNA methylation, chromatin accessibility and 
conformation using whole genome bisulfite sequencing (WGBS), assay for transposase-accessible chromatin-sequencing (ATAC-seq), and chromatin capture using Hi-C, respectively (Aim 1A). To identify direct genomic 
targets of ASCL2 we will perform chromatin immunoprecipitation sequencing (ChIP-seq) in EVT cells (Aim 
1B). ASCL2 regulation of trophoblast development and invasion will then be evaluated in vivo using a newly 
established model of invasive trophoblast cell specific depletion based on breeding Prl7b1 Cre recombinase 
and Ascl2 floxed rats (Aim 2A). To examine ASCL2-positive trophoblast cell development in normal and 
diseased rat placentas we will conduct single cell RNA-sequencing (scRNA-seq) and single cell ATAC-seq 
(Aim 2B). The proposed research plan will provide the candidate with a body of experimental work necessary
for independent publications and preliminary data for R-series grants. During the R00 phase the candidate will 
develop independence from her mentors by identifying targets of ASCL2 and investigating their contributions to 
invasive trophoblast lineage development with innovative rat models. The proposed research project serves as 
the foundation for the candidate’s long-term career goal of identifying how dysregulated spiral artery 
remodeling leads to a spectrum of diseases ranging from fetal growth restriction to preeclampsia.

## Key facts

- **NIH application ID:** 10932408
- **Project number:** 5R00HD107262-04
- **Recipient organization:** CHILDREN'S MERCY HOSP (KANSAS CITY, MO)
- **Principal Investigator:** Kaela Margaret Varberg
- **Activity code:** R00 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $241,882
- **Award type:** 5
- **Project period:** 2023-09-01 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10932408

## Citation

> US National Institutes of Health, RePORTER application 10932408, Regulation of Invasive Trophoblast Cell Lineage Development (5R00HD107262-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10932408. Licensed CC0.

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