DMD Pluripotent Stem Cell Derived Cardiac Cells Recapitulate in vitro Human Cardiac Pathophysiology

Area of Science:

• Cardiovascular Research
• Genetics
• Stem Cell Biology

Background:

• Duchenne muscular dystrophy (DMD) causes progressive cardiomyopathy and heart failure, the primary cause of death in patients.
• Previous research relied on mouse models, lacking human relevance for studying DMD cardiomyocyte (DMD-CM) dysfunction.
• A human model was needed to accurately characterize DMD-CM phenotype and symptom onset.

Purpose of the Study:

• To create and validate a human Duchenne muscular dystrophy cardiac cell (DMD-CC) disease model.
• To investigate the functional and molecular consequences of dystrophin deficiency in human cardiac cells.
• To establish a platform for studying DMD cardiomyopathy progression and in vitro therapy testing.

Main Methods:

• Generation of dystrophin-deficient human pluripotent stem cell (hPSC) lines from DMD patients and via CRISPR/Cas9.
• Differentiation of DMD-hPSCs into cardiac cells (DMD-CCs).
• Assessment of differentiation efficiency, cell death rates, ion channel expression, calcium handling, mechanical function, and adrenergic response.

Main Results:

• DMD-hPSCs showed reduced differentiation into cardiac cells.
• DMD-CCs exhibited increased cell death, altered potassium and calcium handling (Kir2.1 and dihydropyridine receptor overexpression).
• DMD-CCs displayed impaired contractility, bradycardia, increased heart rate variability, and blunted beta-adrenergic response.

Conclusions:

• The developed human DMD-CC model accurately recapitulates key functional defects and cardiac wasting seen in Duchenne muscular dystrophy.
• Dystrophin deficiency directly impacts human cardiac cell function, leading to observable mechanical and electrophysiological impairments.
• This novel in vitro model serves as a valuable tool for advancing the study of DMD-associated cardiomyopathy and evaluating potential therapeutic interventions.