# Molecular regulators of human amniogenesis

> **NIH NIH R01** · MEDICAL COLLEGE OF WISCONSIN · 2024 · $578,818

## Abstract

Project Summary
The amniotic membrane forms a tough fluid-filled sac that protects the developing embryo and is essential for
a successful pregnancy. Amniogenesis initiates early in human development as the embryo implants into the
uterine wall: the epiblast cells first polarize to form a pluripotent lumenal cyst and, subsequently, one half of
this polarized cyst loses pluripotency and becomes squamous amniotic ectoderm while the other side remains
pluripotent. In published work using an hPSC-based Gel-3D system, we showed that a mechanical cue
initiates amnion specification by triggering a BMP signaling cascade in individual cells of pluripotent cysts.
Recently, we established a new hPSC-based amniogenic model called Glass-3D+BMP, in which the mechanical
cue is bypassed and uniform addition of BMP ligand to pluripotent hPSC cysts leads to simultaneous activation
of BMP signaling in all cells within 10 minutes. Over the next 48 hours, all cells give rise to squamous amnion
cells, forming fully squamous amnion cysts. This highly robust amniogenic system, which enables reproducible
mechanistic analyses specifically into amniogenesis, will be used throughout this study to investigate
transcriptional, signaling and epigenetic machineries driving amnion fate progression. Interestingly, although all
cells are equally exposed to BMP in the Glass-3D+BMP model, amniogenesis initiates focally then spreads
laterally to form fully squamous amnion cysts. Importantly, similar focal amniogenesis followed by spreading
was also seen in the Gel-3D amniogenic system that we previously developed. Moreover, in early cynomolgus
macaque embryos, molecular signatures associated with focal initiation followed by spreading are readily seen
at transcript and protein levels, indicating that this two-step process is an important aspect of successful
amnion fate determination both in vivo and in vitro. The goal of this proposal is to understand the mechanisms
that initiate (Aim 1) and spread (Aim 2) amnion fate specification. In vitro findings will be grounded using early
cynomolgus macaque embryo samples. Our preliminary loss-of-function data lead us to hypothesize that
GATA2 and GATA3 are critical for focal initiation of amniogenesis, while spreading is controlled by TFAP2A
and canonical WNT signaling. Proposed transcriptomic and epigenetic studies will further expose these
transcriptional and signaling machineries. Functional genetic deletion studies of candidate genes will be used
to test for potential master regulators of amnion fate. Overall, the work proposed here will greatly accelerate
the pace of discovery regarding critical but previously inaccessible post-implantation events and thus will have
enormous implications for understanding early processes that impact embryonic development and human
fertility.

## Key facts

- **NIH application ID:** 10979244
- **Project number:** 2R01HD098231-06
- **Recipient organization:** MEDICAL COLLEGE OF WISCONSIN
- **Principal Investigator:** Kenichiro Taniguchi
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $578,818
- **Award type:** 2
- **Project period:** 2019-09-16 → 2029-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10979244

## Citation

> US National Institutes of Health, RePORTER application 10979244, Molecular regulators of human amniogenesis (2R01HD098231-06). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10979244. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*