Background: Abdominal aortic aneurysm (AAA) is usually asymptomatic
and mostly diagnosed incidentally. Aortic dilatation progresses along with the
wall weakening and eventually leads to a life-threatening rupture. Currently, there
are no effective screening biomarkers for AAA. MicroRNAs, a class of small noncoding
RNA molecules, offer great potential as biomarkers because of their stability
in the bloodstream and expression profile specific for different diseases.
Objective: To assess the circulating miR-29c-3p as a potential biomarker of AAA
and to elucidate the biological functions of miR-29c-3p in terms of pathogenesis of
Methods: Two groups of patients scheduled for elective surgery were studied: 52 patients with AAA,
and 51 patients with peripheral artery disease who served as a control group (matched by age and gender).
Serum miRNA was measured for circulating miR-29c-3p using quantitative real-time PCR. Functional
tests of miR-29c-3p impact on the targeted transcripts were studied using its mimic or inhibitor
and a cell culture of endothelial cells.
Results: Serum miR-29c-3p was significantly elevated in AAA patients as compared with controls
(RQ=8.73) and correlated with the diameter of the aneurysm. No association between well-known risk
factors and level of circulating miR-29c-3p was found using a logistic regression. In vitro study revealed
that miR-29c-3p suppressed transcripts of ELN, COL4A1, PTEN and VEGFA.
Conclusion: The results suggest that elevated miR-29c-3p is a potential serum biomarker for AAA.
Causal involvement of miR-29c-3p in pathogenesis of the disease was found in human vascular endothelial
cells, which extracellular matrix synthesis and integrity maintenance was inhibited.