# Establishment of yolk sac organoids for developmental toxicity assessment

> **NIH NIH R03** · UNIVERSITY OF HAWAII AT MANOA · 2024 · $156,500

## Abstract

Proposal Abstract
 The yolk sac is an extra-embryonic organ that is vital for early embryo development, serving as the
nutrient supply center during the first trimester. It absorbs nutrients and synthesizes lipoproteins, which are
transported to the embryo through the vasculature and blood cells that are also produced by the yolk sac.
Accordingly, severe damage to the yolk sac by environmental insults, such as maternal infection, disease, and
chemical agent, leads to death or maldevelopment of the embryo. An example is diabetic embryopathy, in
which high levels of glucose impair the yolk sac to cause embryo abnormalities. However, our knowledge of
environmental factors that are harmful to the yolk sac is still scarce. More investigations on the yolk sac are
crucial to maintain healthy embryos. Since actual human yolk sac tissue is generally inaccessible, many
studies are conducted using animals, namely rodents, which have provided mechanistic insights into the yolk
sac formation. Notably, distinct differences exist between the yolk sacs of rodents and human, which
necessitate the establishment of human yolk sac models that are amenable to experimental interrogations.
The objective of the proposed project is to create an in vitro yolk sac model, or yolk sac organoid, using human
pluripotent stem cells, with the long-term goal of utilizing it to study the impact of harmful environmental factors.
We have recently developed a culture protocol, which allows aggregates of human pluripotent stem cells to
form large cysts surrounded by blood vessel-like structures. These cysts strongly express various transcripts
that are enriched in the human yolk sac. We hypothesize that these stem cell-derived cysts represent the
morphological and functional properties of the human yolk sac, and can serve as yolk sac organoids to be
used for further investigations. In Aim 1, we will characterize the stem cell-derived cyst at the cellular and
molecular levels to reveal which properties of the human yolk sac are captured. In Aim 2, we will test the roles
of key regulator genes in the yolk sac-like cyst formation to assess functional similarities between the rodent
and human yolk sacs. In Aim 3, we will examine the effects of high glucose levels on the yolk sac-like cyst
formation to provide insights into the mechanisms underlying diabetic embryopathy. The proposal is significant
because it aims to establish an experimentally tractable model of the human yolk sac. As the yolk sac is a vital
organ to support embryo development, understanding of its susceptibility to environmental disturbances is
crucial to ensure a healthy pregnancy. An in vitro model made of human pluripotent stem cells should be of
great value to facilitate investigations on the human yolk sac. The proposal is innovative because the creation
of an organoid that represents the human yolk sac at the morphological and functional level is highly unique,
and the idea of applying the yolk sac organoid to disc...

## Key facts

- **NIH application ID:** 10989052
- **Project number:** 1R03ES035972-01A1
- **Recipient organization:** UNIVERSITY OF HAWAII AT MANOA
- **Principal Investigator:** YUSUKE MARIKAWA
- **Activity code:** R03 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $156,500
- **Award type:** 1
- **Project period:** 2024-09-13 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10989052

## Citation

> US National Institutes of Health, RePORTER application 10989052, Establishment of yolk sac organoids for developmental toxicity assessment (1R03ES035972-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10989052. Licensed CC0.

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