Abstract 15773: Direct Profiling of MicroRNA in Thoracic Aortic Aneurysms: Relationship to Aortic Expansion and Growth
Objective: MicroRNAs (miRs) are short non-coding RNAs that are expressed endogenously and function to inhibit gene expression through transcriptional and post-transcriptional mechanisms. While altered miR expression levels have been associated with pathological conditions, their role in regulating gene expression during thoracic aortic aneurysm (TAA) development remains undefined. Accordingly, the present studied examined the expression levels of four specific aortic miRs which function to regulate cellular growth/differentiation and tissue remodeling in aortic specimens from patients with ascending TAAs.
Methods: MicroRNA was isolated from aortic tissue, acquired at the time of surgical resection, from patients with ascending TAAs and tricuspid aortic valves (n=30). Specimens were stratified into 3 size cohorts (10/group) and compared to normal aortic specimens (n=10) obtained from patients without aortic disease. The expression levels of miR- (1, 21, 29a, and 133a) were determined by quantitative real-time PCR.
Results: were expressed as a percent change from normal aorta (mean±SEM), and the relationship between miR expression and aortic size was determined.
Results: Expression of each of the miRs was altered in the TAA specimens as compared to normal aorta. More importantly, decreasing expression levels of three miRs (miR-1, miR-21, and miR-29a) demonstrated a significant relationship with increasing aortic diameter.
Conclusions: The unique findings from this study demonstrate a significant relationship between the loss miR expression and enhancement of aortic diameter in patients with ascending TAAs. These results identify the dysregulation of specific miRs that target genes which regulate aortic cellular phenotype and extracellular matrix remodeling, and may contribute to aortic expansion and growth in aneurysm disease.
- © 2010 by American Heart Association, Inc.