Identification and characteristics of microRNAs in rat abdominal aortic aneurysms

Abdominal aortic aneurysm (AAA) is a lethal disease, occurring mostly in men more than 65 years of age. Until recently, the pathogenesis of AAA remains poorly understood. MicroRNAs (miRNAs) are a novel class of endogenous small noncoding RNAs that play important roles in diverse biological and pathological processes and was more recently investigated in cardiovascular physiology and pathology. In this study, we employed microarray to detect and compare miRNA expressions of AAAs in rats. Four miRNAs were validated using real time RT-PCR. Functional annotations of putative targets of deregulated miRNAs via bioinformatics approaches revealed that predicted targets were highly enriched and involved in several signaling pathways important for AAA formation. Our results indicate that miRNAs are extensively involved in rat AAA formation and provide a global view of AAA miRNA profiles, which is expected to provide new clues to develop targeted therapies against this calamitous disease. Sprague-Dawley rat AAA model was established by calcium chloride and collagenase co-incubation method. After 28 days, three rats with confirmed AAAs and three normal rats form control(sham operation) group were euthanized and the aortas specimens were used for this experiment.