Abstract 10348: Discovery of Novel Mechanosensitive mRNA and miRNA in Vivo Using Mouse Carotid Artery Endothelium Exposed to Disturbed Flow
Recently, we showed that disturbed flow caused by a partial ligation of mouse carotid artery rapidly induces atherosclerosis, demonstrating direct causal link between flow and atherosclerosis. The mechanisms, however, by which disturbed flow induces atherosclerosis is still unclear. Here, we identified mechanosensitive genes, both mRNAs and miRNAs, in vivo, through a genome-wide microarray study using mouse endothelial RNAs directly isolated from the flow-disturbed left and the undisturbed right common carotid artery (LCA and RCA). We found 62 and 523 mRNAs that changed significantly by 12hr and 48hr post-ligation. The results were validated by qPCR for 44 of 46 tested mRNAs. This array study discovered numerous novel mechanosensitive genes including Lmo4, klk10 and dhh, while confirming well-known ones such as Klf2, eNOS, and BMP4. Comparison of in vivo, ex vivo, and in vitro endothelial mRNA expression profiles indicates that numerous in vivo mechanosensitive mRNAs appear to be lost or dysregulated during culture. In addition, we also identified 45 (27 up- and 18 downregulated) of 656 miRNAs significantly altered in the flow disturbed LCA endothelium by 48 hours post-ligation. The results were validated for 7 of 14 tested miRNAs by qPCR. Bioinformatics analyses were performed to discover the correlation between the potential target mRNAs regulated by flow-sensitive miRNAs. Approximately 10% (56/523) of mechanosensitive mRNAs were found to be potential targets of shear-sensitive miRNAs. This study provides an overview of the complex networks of gene expressions regulated by disturbed flow in vivo. Determining the functional importance of these novel mechanosensitive genes may provide important insights into understanding vascular biology and atherosclerosis.
- © 2010 by American Heart Association, Inc.