Abstract P640: Endogenous microRNAs in Human Microvascular Endothelial Cells Regulate mRNAs Encoded by Hypertension-Related Genes and Are Functionally Important
Relatively few miRNA-target pairs have been shown to be involved in hypertension or physiological processes related to blood pressure regulation. The goal of the present study was to systematically identify endogenous microRNAs in endothelial cells that regulate mRNAs encoded by genes relevant to hypertension. Small RNA deep sequencing was performed in cultured human microvascular endothelial cells (HMVEC-D) to identify abundant miRNAs. Of the 50 most abundant microRNAs identified, 30 had predicted target mRNAs encoded by genes with known involvement in hypertension or blood pressure regulation. HMVEC-D were transfected with anti-miR oligonucleotides to inhibit each of the 30 microRNAs and the mRNA abundance of predicted targets was measured by qRT-PCR. Of 95 microRNA-target pairs examined, the target mRNAs were significantly up-regulated in 35 pairs and paradoxically down-regulated in 8 pairs. The functional relevance of miRNAs targeting JAG1 (miR-21-5p) and NOX4 (miR-92a-3p, miR-92b-3p, miR-100-5p, and miR-99b-5p), was tested in in vivo and in vitro models, respectively. Blood pressure was measured with radiotelemetry in C57BL/6J mice receiving LNA anti-miR-21 or scrambled LNA anti-miR (n=4/group; 10mg/kg; i.p.). LNA anti-miR-21 induced a transient increase in arterial pressure in mice fed a 0.4% NaCl diet, but a significant and sustained reduction of 24 hour averaged mean arterial pressure on a 4.0% NaCl diet, reaching 96.3 ± 4.0 mmHg compared to 105.3 ± 1.6 mmHg (mean ± SEM) in mice treated with scrambled anti-miR (p<0.05). The release of H2O2 from HMVEC-D was measured by Amplex Red assay 48 hours after transfection with anti-miRs identified to increase NOX4 mRNA abundance or scrambled anti-miR (n=6-12/group). The release of H2O2 from HMVEC-D was significantly increased following transfection of anti-miRs for miR-92a-3p, miR-92b-3p, miR-99b-5p, and miR-100b-5p by 82.2% to 139.6%. These findings indicate widespread, tonic control of mRNA abundance of genes relevant to blood pressure regulation by endothelial microRNAs that are functionally significant.
Author Disclosures: A.J. Kriegel: None. M.A. Baker: None. Y. Liu: None. P. Liu: None. A.W. Cowley: None. M. Liang: None.
- © 2015 by American Heart Association, Inc.