Dynamic microRNA expression during the transition from right ventricular hypertrophy to failure

Area of Science:

• Cardiovascular Biology
• Molecular Cardiology
• Gene Regulation

Background:

• MicroRNAs (miRs) are key regulators of cardiac remodeling in left ventricular hypertrophy (LVH) and failure (LVF).
• The role of miRs in right ventricular hypertrophy (RVH) and failure (RVF) remains largely unexplored.
• The right ventricle (RV) is particularly vulnerable in conditions like congenital heart disease and systemic RVs.

Purpose of the Study:

• To investigate the role of miRs in the development of RVH and RVF.
• To identify specific miRs and their target genes involved in RV remodeling.
• To compare miR expression patterns between RV and left ventricle (LV) under stress.

Main Methods:

• Development of a murine model of RVH and RVF using pulmonary artery constriction (PAC).
• Comprehensive miR microarray analysis of RV tissue from PAC-induced RVH/RVF and control groups.
• Bioinformatic analysis to identify miR targets and associated gene regulatory pathways.

Main Results:

• Significant alterations in miR expression were observed in RVH/RVF, including upregulation of miR 199a-3p (cardiomyocyte growth) and miR-208b (fetal gene program).
• Apoptosis and fibrosis-associated miRs (miR-34, miR-21, miR-1) were implicated in the transition to heart failure.
• Four miRs (miR-34a, miR-28, miR-148a, miR-93) were uniquely upregulated in RVH/RVF compared to LVH/LVF, with corresponding downregulation of target genes involved in cell survival and metabolism.

Conclusions:

• This study provides the first comprehensive analysis of miR alterations during RV remodeling leading to RVH and RVF.
• Identified miRs and their targets offer insights into RV-specific pathobiology and potential therapeutic strategies.
• Differential miR regulation between RV and LV may explain the RV's heightened susceptibility to heart failure.