Regional Differences in mRNA and lncRNA Expression Profiles in Non-Failing Human Atria and Ventricles

Area of Science:

• Cardiovascular Biology
• Molecular Cardiology
• Genomics

Background:

• The four human heart chambers (atria and ventricles) have distinct functions and are variably impacted by cardiovascular diseases.
• Understanding the molecular basis of these chamber-specific functions is essential for comprehending cardiac health and disease.

Purpose of the Study:

• To investigate the molecular differences, specifically mRNA and lncRNA expression profiles, among the distinct chambers of the non-failing human heart.
• To identify chamber-specific and gender-specific gene expression patterns.

Main Methods:

• Examined mRNA and lncRNA expression profiles in the left atrium (LA), right atrium (RA), left ventricle (LV), right ventricle (RV), and interventricular septum (IVS) of non-failing human hearts (N=8).
• Analyzed paired atrial and ventricular samples (n=40) using differential expression analysis (>1.5 fold change; FDR < 0.05).
• Utilized Gene Ontology classification to identify enriched signaling pathways.

Main Results:

• Identified 5,747 differentially expressed mRNAs and 2,794 differentially expressed lncRNAs between heart chambers.
• Found substantial transcriptomic differences between atrial and ventricular samples, with 17-28% of transcripts showing differential expression.
• Revealed heterogeneities in expression within atria and ventricles, as well as gender-specific differences in gene and lncRNA profiles.

Conclusions:

• Significant molecular heterogeneity exists across human heart chambers at the mRNA and lncRNA levels.
• These chamber-specific expression profiles are likely fundamental to normal cardiac function and may influence susceptibility to cardiovascular disease.
• Gender also contributes to variations in cardiac gene expression patterns.