RNA-binding protein SAMD4A targets FGF2 to regulate cardiomyocyte lineage specification from human embryonic stem...

Area of Science:

• Cardiovascular Biology
• Stem Cell Biology
• Molecular Mechanisms of Development

Background:

• RNA-binding proteins (RBPs) play vital roles in cardiac development.
• Many RBPs involved in heart development remain uncharacterized.

Purpose of the Study:

• To investigate the role of SAMD4A in cardiomyocyte lineage specification.
• To elucidate the molecular mechanisms by which SAMD4A influences cardiac development.

Main Methods:

• Utilized a human embryonic stem cell (hESC) differentiation model into cardiomyocytes.
• Generated SAMD4A-knockdown and SAMD4A-overexpressing hESC lines.

Main Results:

• SAMD4A expression increases during early heart development.
• SAMD4A suppression impairs hESC proliferation, cardiac mesoderm differentiation, and cardiomyocyte function.
• SAMD4A binds FGF2 mRNA, stabilizing it and enhancing translation, thus upregulating FGF2 and modulating AKT signaling.
• FGF2 supplementation rescues proliferation defects caused by SAMD4A absence.

Conclusions:

• SAMD4A is essential for cardiomyocyte lineage commitment via post-transcriptional regulation of FGF2 and AKT signaling modulation.
• This study highlights SAMD4A's role in cardiac organogenesis.
• Findings provide insights into heart development mechanisms and potential therapeutic strategies for congenital heart disease.