Role of microRNAs in vascular diseases
All atheroma, blockages in the artery wall, carry a risk of rupture of the wall and clinical complications. Followed by formation of a clot, this could lead to an acute medical situation. Recent studies have pointed to some microRNAs (miRNAs) that modulate processes involved in atherothrombosis. The MIRNAVASC (Role of microRNAs in vascular diseases) project has investigated two implicated miRNAs in particular, miRNA-595 and miRNA-32*. These small molecules are linked with cell death, apoptosis, and have been reported as more abundant in the serum of abdominal aortic aneurysm (AAA) patients when compared with healthy individuals. Aneurysm involves the elastic medial of the artery wall where there is significant loss of smooth muscle cells (SMCs). Being the major source of extracellular matrix proteins, SMC depletion may cause a reduction of tissue repair. The MIRNAVASC team therefore looked at the miRNA expression of AAA patients compared to healthy age-matched controls. Research results showed there was an upregulation of the miRNA genes miR-32* and miR-595 in aneurysm tissue. This suggests that these miRNAs could have an important role in changes in the wall during AAA. Moreover, when the scientists looked at one type of apoptosis induced by staurosporine they found that both miRNAs were able to induce cell death without staurosporine treatment. The pair of miRNAs can also modulate the expression of apolipoprotein H (Apo H). Apo H is an abundant plasma glycoprotein that protects endothelial cells, macrophages and vascular SMCs from cell death. Recent evidence points to a role played by exosomes in delivery of miRNA-32* and miRNA-595 in the serum and this is a mechanism of communication between cells, including SMCs. Further research is needed to investigate the possible link between this and damage to the muscle cells. An in-depth knowledge of the biochemistry of atherothrombosis and its damage to artery walls could be applied in diagnosis, prognosis and therapeutic settings. As this disease is the major cause of death in developed countries, this has vast implications for healthcare.
Keywords
Thrombosis, artery, atherothrombosis, microRNAs, MIRNAVASC, miRNA-595, miRNA-32*
