Electrophysiologic Characterization of Calcium Handling in Human Induced Pluripotent Stem Cell-Derived Atrial...

Area of Science:

• Cardiovascular Biology
• Stem Cell Research
• Molecular Cardiology

Background:

• Human induced pluripotent stem cell (hiPSC)-derived atrial cardiomyocytes (CMs) are crucial for studying atrial fibrillation (AF).
• Understanding the molecular and electrophysiological characteristics of these cells is essential for accurate arrhythmia modeling.

Purpose of the Study:

• To comprehensively analyze the molecular and electrophysiological phenotype of retinoic acid (RA)-guided atrial-like hiPSC-CMs.
• To elucidate the mechanism by which RA influences calcium ion homeostasis and electrophysiology in these cells.

Main Methods:

• Performed comprehensive molecular, transcriptomic, and electrophysiologic analyses.
• Investigated the interaction between RA, its receptor, and chicken ovalbumin upstream promoter-transcription factor 2 (COUP-TFII).
• Assessed the downstream effects of COUP-TFII on calcium handling and gene expression.

Main Results:

• RA significantly altered the expression of genes related to calcium ion homeostasis in hiPSC-CMs.
• Identified a direct interaction between RA and COUP-TFII, a key regulator of atrial electrophysiology.
• Demonstrated that RA induces an atrial-like electrophysiologic signature via COUP-TFII-mediated regulation of calcium channel gene expression and calcium handling.

Conclusions:

• RA treatment effectively generates atrial-like hiPSC-CMs with a distinct electrophysiological profile.
• The RA-COUP-TFII pathway is critical for establishing atrial-like calcium handling and electrophysiology.
• These findings support the utility of RA-guided hiPSC-CMs for modeling AF and understanding its underlying mechanisms.