Cardiomyocyte nuclearity and ploidy: when is double trouble?

Area of Science:

• Cardiovascular Biology
• Cellular Biology
• Developmental Biology

Background:

• Mammalian cardiomyocytes (CMs) lose their proliferative capacity during development, transitioning from replicating cells to a mature state.
• Understanding this transition is crucial for cardiac repair, as inducing CM replication could restore function in damaged hearts.

Purpose of the Study:

• To review the mechanisms behind the loss of cardiomyocyte proliferation.
• To explore the role of multinucleation and polyploidy in mature cardiomyocytes.
• To investigate the applicability of the myonuclear domain (MND) concept to cardiomyocytes and its relation to CM multinucleation.

Main Methods:

• Literature review focusing on cardiomyocyte cell cycle regulation.
• Analysis of studies on multinucleation and polyploidy in cardiomyocytes.
• Exploration of the myonuclear domain (MND) concept in skeletal muscle and its potential translation to cardiac muscle.

Main Results:

• Mature mammalian cardiomyocytes are often multinucleated and polyploid, a state potentially linked to physiological function but also disadvantageous in certain contexts.
• The myonuclear domain (MND) concept, established in skeletal muscle, may be relevant to cardiomyocytes, potentially influencing their multinucleation.
• Cardiomyocyte nuclei integrate biochemical and mechanical signals, influencing gene expression and replication.

Conclusions:

• The transition of cardiomyocytes to a non-proliferative, multinucleated state is a key developmental event with significant clinical implications.
• The myonuclear domain (MND) concept offers a potential framework for understanding cardiomyocyte nuclear function and multinucleation.
• Further research into the multimodal integration function of cardiomyocyte nuclei could reveal novel therapeutic targets for cardiac regeneration.