miR-29c-3p is an Effective Biomarker of Abdominal Aortic Aneurysm in Patients Undergoing Elective Surgery

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 aneurysms. 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.