# Defining the downstream genetic networks regulated by GATA6 during human cardiogenesis using iPSC and hESC models

> **NIH NIH F32** · WEILL MEDICAL COLL OF CORNELL UNIV · 2022 · $73,942

## Abstract

ABSTRACT
Genetic loss-of-function studies in model organisms have elucidated that the GATA family of transcription factors
regulate crucial aspects of heart morphogenesis including early germ layer patterning and cardiac progenitor cell
specification and differentiation. Importantly, heterozygotic mutations of the cardiogenic factor GATA6 in humans
are associated with various forms of congenital heart disease (CHD) such as outflow tract and septal defects.
The phenotypic diversity of CHD in patients containing these GATA6 mutations is likely due an unknown
combination of variants in modifying or interacting genes that converge to influence the cardiac phenotype. A
greater understanding of the GATA6 genetic regulatory network that controls human heart development is thus
essential for advancing therapies. Here, I propose utilizing cardiac-directed differentiating human pluripotent
stem cells (hPSCs) as a system to study GATA6 function. Preliminary evidence showed that GATA6-/- hPSCs
failed to generate cardiomyocytes or express markers of cardiac progenitors, and had reduced cardiac
mesoderm marker expression during cardiac-directed differentiation compared to wild-type (WT) controls.
Furthermore, GATA6+/- hPSCs generated cardiomyocytes less efficiently and had reduced cardiac progenitor
marker gene expression compared to WT cells, revealing a phenotype in GATA6 heterozygotes that has not
been reported in previous animal studies. Based on these data, I aim to study GATA6 function during cardiac
mesoderm patterning and GATA6 haploinsufficiency during cardiogenesis through two Specific Aims. In Aim 1,
I plan to discover the function of GATA6 during the earliest stages of human cardiogenesis. Two candidate
downstream targets of GATA6 activity identified from RNA-seq data, LGR5 and RIPPLY1, will first be studied
through genetic gain- and loss-of-function studies. GATA6 ChIP-seq and ATAC-seq will also be performed in
GATA6-/- and WT cells during early stages of cardiac differentiation to identify direct targets of GATA6 and
regulatory genes affected by chromatin inaccessibility, respectively. In Aim 2, I propose to define the
consequence of human GATA6 haploinsufficiency during cardiogenesis. An induced pluripotent stem cell (iPSC)
line was created from a CHD patient containing a heterozygous mutation in GATA6 (c.1071delG) that
differentiates to cardiomyocytes less efficiently than a WT iPSC line. Here, engineered GATA6+/- hESCs and
patient-derived GATA61071delG/+ iPSCs will be differentiated to cardiomyocytes and examined at distinct stages of
cardiogenesis to carefully define the cardiac phenotype. GATA6+/- cells have increased expression of retinoic
acid (RA) signaling related genes, which may underlie the cardiac phenotype. RA signaling will thus be inhibited
with the goal of rescuing the phenotype of GATA6 haploinsufficiency. Finally, the transcriptomes of differentiating
GATA6+/- hESC and patient-derived iPSC lines will be analyzed using RNA-seq t...

## Key facts

- **NIH application ID:** 10460286
- **Project number:** 5F32HL152575-03
- **Recipient organization:** WEILL MEDICAL COLL OF CORNELL UNIV
- **Principal Investigator:** Joseph A Bisson
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $73,942
- **Award type:** 5
- **Project period:** 2020-06-01 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10460286

## Citation

> US National Institutes of Health, RePORTER application 10460286, Defining the downstream genetic networks regulated by GATA6 during human cardiogenesis using iPSC and hESC models (5F32HL152575-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10460286. Licensed CC0.

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