Transient Notch Activation Converts Pluripotent Stem Cell-Derived Cardiomyocytes Towards a Purkinje Fiber Fate

Area of Science:

• Cardiovascular Biology
• Stem Cell Biology
• Electrophysiology

Background:

• Cardiac Purkinje fibers are essential for coordinated heart contraction and implicated in ventricular arrhythmias.
• Generating Purkinje fiber cells from human pluripotent stem cells is challenging, limiting research into conduction system defects.

Purpose of the Study:

• To identify signaling pathways involved in Purkinje fiber formation.
• To investigate the potential of Notch signaling to convert human pluripotent stem cell-derived cardiomyocytes into Purkinje fiber cells.

Main Methods:

• Analysis of single-cell RNA sequencing data from murine embryonic hearts.
• In vitro activation of Notch signaling in human pluripotent stem cell-derived cardiomyocytes.
• Electrophysiological recordings and RNA sequencing of modified cardiomyocytes.
• Development and validation of in silico models for drug response prediction.

Main Results:

• Notch activation induced Purkinje fiber-like electrophysiological properties and gene expression profiles (SCN5A, HCN4, ID2) in cardiomyocytes.
• Notch-induced cells exhibited reduced contractile force.
• In silico models predicted differential drug responses between Purkinje fiber cells and cardiomyocytes.
• In vitro validation confirmed model predictions for anti-arrhythmic drug efficacy.

Conclusions:

• Notch signaling is a key pathway for generating Purkinje fiber-like cells from human pluripotent stem cells.
• This novel cell model advances understanding of Purkinje fiber physiology and cardiac conduction disorders.
• The developed in silico and in vitro models offer a platform for studying drug effects on cardiac conduction and arrhythmias.