Role of Circulating MicroRNAs in Pathogenesis of Aneurysms of the Abdominal and Thoracic Aorta - Study "Micro AAA"

Aneurysm of the abdominal and thoracic aorta represents a major cause of cardiovascular morbidity and mortality. The course of this condition can stay asymptomatic for long, and its first manifestation can be acute rupture of the aneurysm sac with life-threatening bleeding. Detection of patients at risk and their early treatment significantly reduce the percentage of this potentially lethal complications.

Aortic diseases are most often degenerative processes with a varying involvement of genetic predisposition. In literature, a substantial number of genes were proved to affect the metabolism of the vessel wall and to determine production of structural proteins, which were associated with the vascular pathologies. Pathophysiologic mechanisms of lesions of the aortic wall have not been completely understood. Among other, they include endothelial dysfunction, chronic inflammation of the vessel wall, apoptosis of smooth muscle cells and degradation of the extracellular matrix, resulting in the loss of integrity of layers of the vessel wall and decrease in its strength, which leads to dilation, rupture or dissection. Apart from mutations in genes coding the structural proteins of the vessel wall, many other potential biomarkers were proposed for early diagnosis of aortic aneurysm. These include microRNA (miRNA), one-fibre chains of non-coding ribonucleic acid which are several nucleotides long and are involved in the gene expression through the mechanism of inhibition of mRNA translation or increase in its degradation. Recently, association of levels of these miRNAs to presence and growth of aortic aneurysms has been described.