RAD-Deficient Human Cardiomyocytes Develop Hypertrophic Cardiomyopathy Phenotypes Due to Calcium Dysregulation

Area of Science:

• Cardiology
• Molecular Biology
• Biochemistry

Background:

• Ras associated with diabetes (RAD) regulates cardiac L-type Ca2+ channels (LTCC).
• RAD defects disrupt intracellular calcium dynamics, potentially causing cardiac hypertrophy.
• Understanding RAD deficiency's role in cardiac hypertrophy requires reliable human disease models.

Purpose of the Study:

• To investigate the pathological mechanisms of RAD deficiency in cardiac hypertrophy using a human cell model.
• To determine if RAD disruption affects cardiomyocyte differentiation and function.
• To explore the role of calcium dysregulation in RAD deficiency-induced cardiac hypertrophy.

Main Methods:

• CRISPR/Cas9 gene editing was used to create a RRAD-/- H9 cell line.
• Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) were differentiated from the engineered cell line.
• Intracellular calcium levels and calcium regulation were analyzed in RAD-deficient hESC-CMs.

Main Results:

• RAD disruption did not impede cardiomyocyte differentiation efficiency.
• RAD-deficient hESC-CMs exhibited a hypertrophic phenotype in vitro.
• Elevated intracellular calcium and abnormal calcium regulation were identified as core mechanisms of RAD deficiency-induced cardiac hypertrophy.

Conclusions:

• RAD deficiency leads to cardiac hypertrophy through impaired calcium regulation.
• Management of calcium dysregulation can prevent cardiac hypertrophy development in vitro.
• The RRAD-/- hESC-CM model provides a platform for studying RAD deficiency-related cardiac pathology.