Transcriptomic Analysis of Cardiomyocyte Extracellular Vesicles in Hypertrophic Cardiomyopathy Reveals Differential...

Area of Science:

• Cardiovascular Biology
• Stem Cell Biology
• Molecular Medicine

Background:

• Hypertrophic cardiomyopathy (HCM) is a genetic heart muscle disease characterized by left ventricular hypertrophy.
• The underlying molecular mechanisms driving HCM phenotypes, including heart failure and sudden cardiac death, remain incompletely understood.
• Human models are crucial for elucidating HCM pathogenesis and developing targeted therapies.

Purpose of the Study:

• To investigate the molecular consequences of an HCM-associated mutation (c.ACTC1^G301A) using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).
• To analyze cellular and extracellular vesicle (EV) transcriptomes under varying contractile workloads.
• To identify novel mechanisms and potential therapeutic targets for HCM.

Main Methods:

• Generation of hiPSC lines from HCM patients and isogenic controls using CRISPR/Cas9 gene editing.
• Differentiation of hiPSCs into hiPSC-CMs and analysis at baseline and increased contractile workload (2 Hz stimulation).
• Isolation and characterization of extracellular vesicles (EVs) and transcriptomic analysis of both cells and EVs.

Main Results:

• HCM mutation induced differential splicing and disrupted metabolic pathways in hiPSC-CMs.
• Increased contractile workload exacerbated metabolic gene expression disruptions in HCM hiPSC-CMs.
• HCM-derived EVs showed altered small nucleolar RNA (snoRNA) cargo, particularly under increased workload, suggesting roles in post-translational modification and alternative splicing.

Conclusions:

• HCM mutations impact cellular splicing and metabolism, with workload exacerbating these effects.
• EV-associated snoRNAs represent a novel mechanism potentially linking workload, splicing, and HCM phenotypes.
• Identified snoRNAs may serve as future HCM biomarkers or targets for RNA-based therapies.