Abstract 15384: Laminar Flow Regulates Endothelial Cell Metabolism via Long Non-coding RNA lncflow2 (Best of Basic Science Abstract)
Considering that the transcriptome consists largely of non-coding transcripts, we analysed the impact of atheroprotective laminar flow (20 dynes/cm2) on the expression of long non-coding RNAs (lncRNA) in human endothelial cells (EC) by RNA deep sequencing.
Among the significantly up-regulated lncRNAs, we specifically confirmed the up-regulation of lncflow2 upon laminar flow (3.4±1.5, p<0.05) and by overexpressing the flow-induced transcription factor KLF2 (1.95+0.2, p<0.05) by qRT-PCR. Lncflow2 is preferentially localized to the nucleus and RNA immunoprecipitation data indicate an association with the chromatin mark H3K27me3 suggesting that lncflow2 might epigenetically control gene expression.
Functionally, the reduction of lncflow2 using LNA-Gapmers suppressed spheroid sprout formation of ECs (34.7 % reduction, p<0.05) and increased expression of endothelial adhesion molecules suggesting that lncflow2 improves EC function and reduces endothelial inflammation. Furthermore, gene ontology analysis of exon microarray analysis with RNA of lncflow2-silenced ECs revealed a significant regulation of metabolic pathways, such as the mevalonate pathway, indicated by elevated acetyl-CoA-acetyltransferase-2, HMG-CoA-reductase and HMG-CoA-synthase-1 expression (confirmed by RT-PCR; all p<0.05). In this context, inhibition of the HMG-Co-reductase by atorvastatin rescued the diminished spheroid sprouting upon loss of lncflow2. To elucidate additional effects on endothelial metabolic function, a mass spectrometry metabolome screening revealed significant alterations in amino acid, glucose and lipid metabolism. Seahorse analysis confirmed these data showing an elevated respiration and fatty acid oxidation in lncflow2 silenced ECs.
Our data identify lncflow2 as a flow-regulated lncRNA that modifies EC metabolic responses by controlling metabolism-associated genes- particularly of the mevalonate pathway. Thereby, lncflow2 critically modifies EC functions and may play a regulating role in cellular metabolic adaption to stressors.
Author Disclosures: L. Pfisterer: None. T. Hartung: None. K.M. Michalik: None. W. Chen: None. A.M. Zeiher: None. R.A. Boon: None. S. Dimmeler: Consultant/Advisory Board; Modest; Miragen. Research Grant; Significant; ERC, DFG.
- © 2015 by American Heart Association, Inc.