Abstract P625: Non-coding Rna Regulation Of Gene Expression In Angiotensin Ii-induced Vascular Damage

Abstract

Introduction: Non-coding RNAs (ncRNAs), including long ncRNAs (lncRNAs) and microRNAs (miRs), account for ~98% of the transcribed RNAs. They have been shown to play a role in cardiovascular disease. Vascular damage is an early manifestation and a cause of end-organ damage in hypertension. However, it is unknown whether ncRNAs are involved in the development of vascular injury in hypertension. We hypothesize that ncRNA regulation participates in mechanisms of vascular remodeling and plays an important role in the pathophysiology of hypertension. Methods and Results: Ten-week old male C57BL/6 mice were infused or not with angiotensin (Ang) II for 14 days. Systolic blood pressure (BP) determined by telemetry was increased by Ang II infusion compared to control (146±8 vs 113±5 mmHg, P<0.001). Total RNA was extracted from mesenteric arteries for total and small RNA deep sequencing using Illumina HiSeq-2500. Sequences were aligned to the mm10 genome with STAR, annotated and counted using HTSeq-count or miRDeep2. Differential expression analysis was done in R. Differentially expressed (DE) mRNAs (550 up & 266 down), lncRNAs (7 up & 42 down), miRs (23 up & 12 down) were identified in the Ang II-treated group (1.5 fold change, q<0.05). Targetscan was used to predict interactions between DE miRs and the inversely correlated DE mRNAs or DE lncRNAs. MEME Suite was used to predict DE transcription factor binding sites in the promoter region of genes encoding DE mRNAs, lncRNAs and miRs. Cytoscape was used to construct molecular networks integrating the above interactions and the gene expression profile and to perform functional enrichment analysis, which revealed enrichment of extracellular matrix and developmental processes in DE miR-targeting DE mRNAs (q<1E-20). Ten DE miRNAs whose expression levels correlated (P<0.05) with BP were identified, 9 of which are located in a single miRNA cluster that is conserved in humans. Conclusions: We have identified a conserved miRNA cluster that may play a pivotal role in the regulation of vascular damage in hypertension. A sub-network of genes that participates in the interaction between the miRNA cluster and other BP-correlated RNAs was selected for future investigation to identify therapeutic targets.