# Mechanisms for cell signaling in the control of cardiomyogenesis

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 2020 · $388,750

## Abstract

Project Summary/Abstract
Ischemic heart disease resulting in myocardial infarction (MI) and heart failure is the leading cause of morbidity
and mortality in the USA. Irreversible loss of cardiomyocytes (CMs) and excessive fibrosis governed by pro-
fibrotic signaling such as transforming growth factor β (TGF-β) and Rho-associated kinase (ROCK) pathways
are major factors contributing to pathological ventricular remodeling in patients post-MI. It is not known whether
activation of pro-fibrotic signaling inhibits CM regeneration in adult mammalian hearts following MI.
Recently, our laboratory has shown that suppression of TGF-β signaling dramatically enhances the efficiency
of reprogramming fibroblasts into functional CMs, which is likely related to the fact that TGF-β signaling inhibits
production of CMs from embryonic stem cell-derived embryoid bodies, and cardiac progenitor cells (CPCs) in
adult hearts. However, the precise molecular mechanisms by which TGF-β signaling regulates cardiomyocyte
formation or cardiomyogenesis remain elusive and are the focus of this application. We hypothesize that TGF-
β signaling controls cardiomyogenesis through crosstalk with epigenetic regulators. Our preliminary studies
demonstrate novel roles for TGF-β signaling in the control of physical interaction between cardiac transcription
factors such as Tbx5 and epigenetic regulators such as UTX, an H3K27me3 demethylase. Further studies will
define the mechanisms by which the axis of TGF-β signaling-epigenetic modifications regulates
cardiomyogenesis, and the roles of the axis in the control of cardiomyogenesis in developing heart and adult
hearts post-MI. In vitro, we will activate or inhibit TGF-β signaling in fibroblasts expressing cardiogenic
reprogramming factors, and pluripotent stem cells. We will test the hypothesis that TGF-β signaling
regulates cardiomyogenesis in a manner that the effectors of TGF-β signaling such as phosphor-
Smad2/3 and cardiogenic transcription factors, such as Tbx5 compete with each other for binding and
recruiting epigenetic regulators to chromatin. In embryonic hearts, we will suppress TGF-β signaling
globally or in specific types of CPCs to test the hypothesis that suppression of TGF-β signaling
promotes differentiation of CPCs into cardiomyocytes by regulating occupancy of the chromatin
modifiers during cardiac development. In adult heats post-MI, we will suppress TGF-β signaling
globally or in cardiac fibroblasts and examine reprogramming factors-mediated cardiomyogenesis.
We will attempt to test the hypothesis that suppression of TGF-β signaling enhances regeneration of
CMs in the heart following MI. Together, results from these in vitro and in vivo studies should provide
insights into cell signaling, epigenetic regulators and cardiogenic factors controlling
cardiomyogenesis, and should provide the foundation to facilitate development of novel therapeutic
strategies for heart regeneration.

## Key facts

- **NIH application ID:** 9941121
- **Project number:** 5R01HL133230-05
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Kunhua Song
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $388,750
- **Award type:** 5
- **Project period:** 2016-08-01 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9941121

## Citation

> US National Institutes of Health, RePORTER application 9941121, Mechanisms for cell signaling in the control of cardiomyogenesis (5R01HL133230-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9941121. Licensed CC0.

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