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Updated: May 12, 2026
09:41
Visualization of Cell Cycle Variations and Determination of Nucleation in Postnatal Cardiomyocytes
Published on: February 24, 2017
Meis1 regulates postnatal cardiomyocyte cell cycle arrest
Ahmed I Mahmoud1, Fatih Kocabas1, Shalini A Muralidhar1
1Department of Internal Medicine, Division of Cardiology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
Nature
|April 19, 2013
Summary
The neonatal heart regenerates via cardiomyocyte proliferation, but this ability is lost post-birth. Meis1 (a transcription factor) controls this cell cycle, offering a target for heart regeneration therapies.
Area of Science:
- Cardiovascular Biology
- Developmental Biology
- Molecular Cardiology
Background:
- Neonatal mammalian hearts exhibit significant regenerative capacity through cardiomyocyte proliferation.
- This regenerative ability diminishes by postnatal day 7, with mechanisms of cardiomyocyte cell cycle arrest not fully understood.
- The homeodomain transcription factor Meis1 is crucial for cardiac development, but its specific role in cardiomyocytes is unknown.
Purpose of the Study:
- To investigate the role of Meis1 in regulating cardiomyocyte proliferation and cell cycle.
- To determine if Meis1 influences the window of cardiomyocyte regenerative capacity.
- To explore Meis1 as a potential therapeutic target for promoting heart regeneration.
Main Methods:
- Utilized genetic manipulation in mouse models to delete or overexpress Meis1 in cardiomyocytes.
- Assessed cardiomyocyte proliferation and cell cycle status at different postnatal stages and in adult hearts.
- Analyzed the transcriptional targets of Meis1, focusing on cell cycle inhibitors.
Main Results:
- Meis1 deletion in cardiomyocytes extended the postnatal proliferative window and reactivated mitosis in adult cardiomyocytes without impairing cardiac function.
- Meis1 overexpression reduced neonatal cardiomyocyte proliferation and inhibited neonatal heart regeneration.
- Meis1 was found to be essential for the transcriptional activation of CDK inhibitors p15, p16, and p21.
Conclusions:
- Meis1 acts as a critical transcriptional regulator of cardiomyocyte proliferation.
- Meis1 controls the cell cycle exit of cardiomyocytes, thereby limiting heart regeneration.
- Targeting Meis1 presents a potential therapeutic strategy for enhancing cardiac repair and regeneration.
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