Human cardiac stem cells isolated from atrial appendages stably express c-kit

Area of Science:

• Cardiology
• Stem Cell Biology
• Regenerative Medicine

Background:

• In vivo studies using cardiac stem cells (CSCs) for myocardial infarction show limited benefits.
• A lack of understanding of CSC properties in vitro and in vivo may hinder their efficacy.
• Systematic examination of CSC behavior during culture and potential contamination is needed.

Purpose of the Study:

• To investigate CSC adaptation to in vitro culture processes.
• To assess cell contamination in long-term cultured CSCs.
• To establish a reliable method for obtaining pure CSCs for clinical applications.

Main Methods:

• Human CSCs were isolated from atrial appendages using enzymatic dissociation.
• Cells were analyzed for c-kit+/Lin- markers, contamination, and differentiation potential.
• Magnetic-activated cell sorting (MACS) was employed for cell enrichment.

Main Results:

• Native atrial appendages contain <0.036% c-kit+/Lin- cells.
• Without MACS, c-kit+/Lin- cell percentage increased to ~40% in culture (passages 2-8).
• c-kit MACS achieved >80% purity; Lin depletion was unnecessary.
• Enriched CSCs showed strong cardiomyocyte differentiation potential.

Conclusions:

• Enzymatic dissociation combined with c-kit MACS yields pure, stable c-kit+ CSCs from atrial appendages within ~4 weeks.
• This cost-effective method provides sufficient CSCs for myocardial infarction repair clinical trials.
• The protocol ensures CSC purity and differentiation capacity for therapeutic use.