Atrial hiPSC-CM as a Pharmacologic Model to Evaluate Anti-AF Drugs: Some Lessons From I Kur

Area of Science:

• Cardiovascular Research
• Electrophysiology
• Stem Cell Biology

Background:

• Human induced pluripotent stem cells (hiPSC) and derived cardiomyocytes (hiPSC-CM) are used in preclinical atrial fibrillation (AF) research.
• A key question is whether these models replicate the role of atrial potassium currents, like the ultrarapid potassium current (I Kur), in repolarization.

Purpose of the Study:

• To evaluate the methodological issues in using atrial hiPSC-CMs for AF research.
• To assess the potential of I Kur as an antiarrhythmic target by comparing findings across different models.

Main Methods:

• Review of studies on I Kur block in single atrial hiPSC-CMs.
• Comparison with existing literature on I Kur block in human atria and clinical studies.
• Evaluation of experimental conditions affecting atrial hiPSC-CM electrophysiology.

Main Results:

• Some studies in single atrial hiPSC-CMs suggest I Kur block prolongs action potential duration, indicating I Kur as a potential AF treatment target.
• These findings contrast with established literature on human atria and clinical studies.
• Discrepancies suggest that single atrial hiPSC-CM experiments may be misleading under certain conditions.

Conclusions:

• Atrial hiPSC-CMs may not always accurately reflect human atrial electrophysiology.
• Methodological considerations are crucial when interpreting I Kur's role in AF using hiPSC-CMs.
• Further research is needed to validate I Kur as an antiarrhythmic target across animal models, human tissues, and hiPSC-CMs.