Abstract 10918: High-Throughput Sequencing Analysis of microRNA Profile Dynamics in Patients with Advanced Heart Failure Undergoing Ventricular Assist Device Placement in Comparison to Normal Adult and Fetal Cardiac Expression
Background To further elucidate the role of miRNAs in heart failure (HF), we performed a small RNA profiling using next-generation sequencing on cardiac samples from patients with advanced HF in comparison to healthy adult and fetal hearts
Methods Total RNA was extracted using GITC-phenol-chloroform from 3 healthy adult and 3 fetal heart samples (19-23 weeks) and 26 cardiac samples from patients at the time of LVAD implantation and explantation (7 ischemic, ICM, and 6 dilated HF, DCM). Small RNA library preparation for high-throughput sequencing (Illumina GIIx) was performed using barcoded adapters. Sequences were analyzed using an in-house annotation pipeline, analyzed by hierarchical clustering, and by fitting a negative binomial model for identifying significant count differences (p<0.05 with a false detection rate <5%).
Results We obtained 42,739,862 reads of which 25,650,678 represented miRNAs. Differential expression analysis revealed 1) 186 miRNAs in adult and fetal samples (151 up- and 57 downregulated in fetal hearts), 2) 85 miRNAs in normal and ICM samples (65 up- and 20 downregulated in ICM), 3) 49 miRNAs in normal and DCM (40 up- and 9 downregulated). miRNA hsa-miR-499 was the most significantly downregulated in ICM (delta log fold=4, p=8e10-6). The miR-29 family, implicated in fibrogenesis, belonged to the top miRNAs downregulated in fetal samples compared to normal adult samples (delta log fold=5-6, adjusted p<1.2e-10). Consistently higher counts in fetal heart and ICM and DCM samples, irrespective of LVAD placement were observed with miR-122 (delta log fold=5.6 to 13.8, p=9.8e-8 to 1e-12). Of other cardiovascular miRNAs only miR-208a (upregulated) and miR-206 (downregulated, both in fetal hearts compared to healthy adult) had a significantly different read count. LVAD placement did not result in significant changes in DCM. In ICM patients, a significant change in miR-223, miR-451-DICER1, miR-144, miR-486 and miR-3940 was observed.
Conclusions A high proportion of miRNA genes are differentially regulated comparing normal and failing human myocardium. Mechanical unloading through LVAD placement had minimal effect on the miRNA profile in this study.
- © 2011 by American Heart Association, Inc.