A new paradigm for generating high-quality cardiac pacemaker cells from mouse pluripotent stem cells

Area of Science:

• Stem Cell Biology
• Cardiovascular Research
• Regenerative Medicine

Background:

• Cardiac biological pacing (BP) is a promising intervention for bradyarrhythmias.
• Pluripotent stem cells (PSCs) are a key source for cardiac pacemaker cells (PCs), but quality remains a challenge.
• Existing methods for cardiac PC differentiation from PSCs have limitations in yield and efficiency.

Purpose of the Study:

• To develop an improved strategy for generating high-quality cardiac pacemaker cells (PCs) from pluripotent stem cells (PSCs).
• To enhance the yield and characteristics of cardiac PCs for potential use in biological pacing.
• To elucidate the developmental pathway and key regulators of cardiac PC differentiation.

Main Methods:

• Established a dual-marker (Shox2:EGFP; Hcn4:mCherry) mouse PSC reporter line.
• Developed the FSK method, involving stepwise guidance of PSCs and signaling pathway manipulation.
• Utilized single-cell RNA sequencing (scRNA-seq) to map in vitro differentiation trajectories.

Main Results:

• The FSK method significantly increased the yield of SHOX2+; HCN4+ cardiac pacemaker cells (12-42 fold higher than control methods).
• PSC-derived cardiac PCs exhibited typical pacemaker cell characteristics.
• Single-cell RNA sequencing revealed an in vitro differentiation trajectory resembling in vivo development, identifying ZFP503 as a key regulator.

Conclusions:

• The FSK method represents a significant advancement in producing high-quality cardiac pacemaker cells from PSCs.
• These PSC-derived cardiac PCs hold potential for improving cardiac biological pacing technology.
• The findings contribute to understanding pacemaker cell (patho)physiology and facilitate drug discovery for related diseases.