Detailed characterization of microRNA changes in a canine heart failure model: Relationship to arrhythmogenic structural remodeling

• Published in: Journal of molecular and cellular cardiology 2014-12, Vol.77, p.113-124
• Main Authors: Chen, Yu, Wakili, Reza, Xiao, Jiening, Wu, Chia-Tung, Luo, Xiaobin, Clauss, Sebastian, Dawson, Kristin, Qi, Xiaoyan, Naud, Patrice, Shi, Yan-Fen, Tardif, Jean-Claude, Kääb, Stefan, Dobrev, Dobromir, Nattel, Stanley
• Format: Article
• Language: English
• Subjects: Animals; Arrhythmias, Cardiac - metabolism; Cardiovascular; Collagen Type I - metabolism; Dogs; Extracellular Matrix - metabolism; Fibroblasts - metabolism; Fibrosis; Heart Atria - pathology; Heart failure; Heart Failure - metabolism; Heart Ventricles - pathology; MicroRNA; MicroRNAs - genetics; MicroRNAs - metabolism; Myocardium - metabolism; Myocytes, Cardiac - metabolism; Organ Specificity; Remodeling; Transcriptome; Ventricular Remodeling
• ISSN: 0022-2828; 1095-8584
• DOI: 10.1016/j.yjmcc.2014.10.001

Abstract Heart failure (HF) causes left-atrial (LA) and left-ventricular (LV) remodeling, with particularly-prominent changes in LA that create a substrate for atrial fibrillation (AF). MicroRNAs (miRs) are potential regulators in cardiac remodeling. This study evaluated time-dependent miR expression-changes in LA and LV tissue, fibroblasts and cardiomyocytes in experimental HF. HF was induced in dogs by ventricular tachypacing (varying periods, up to 2 weeks). Following screening-microarray, 15 miRs were selected for detailed real-time qPCR assay. Extracellular matrix mRNA-expression was assessed by qPCR. Tachypacing time-dependently reduced LV ejection-fraction, increased LV-volume and AF-duration, and caused tissue-fibrosis with LA changes greater than LV. Tissue miR-expression significantly changed in LA for 10 miRs; in LV for none. Cell-selective analysis showed significant time-dependent changes in LA-fibroblasts for 10/15 miRs, LV-fibroblasts 8/15, LA-cardiomyocytes in 6/15 and LV-cardiomyocytes 3/15. Cell-expression specificity did not predict cell-specificity of VTP-induced expression-changes, e.g. 4/6 cardiomyocyte-selective miRs changed almost exclusively in fibroblasts (miR-1, miR-208b, miR133a/b). Thirteen miRs directly implicated in fibrosis/extracellular-matrix regulation were prominently changed: 9/13 showed fibroblast-selective alterations and 5/13 LA-selective. Multiple miRs changed in relation to associated extracellular-matrix targets. Experimental HF causes tissue and cell-type selective, time-dependent changes in cardiac miR-expression. Expression-changes are greater in LA versus LV, and greater in fibroblasts than cardiomyocytes, even for most cardiomyocyte-enriched miRs. This study, the first to examine time, chamber and cell-type selective changes in an experimental model of HF, suggests that multiple miR-changes underlie the atrial-selective fibrotic response and emphasize the importance of considering cell-specificity of miR expression-changes in cardiac remodeling paradigms.