Extracellular Matrix Remodelling and Abdominal Aortic Aneurysm

Abstract

Aorta is the largest artery in the body. Aortic wall is comprised of an intricate arrangement of extracellular matrix (ECM) structural proteins, primarily collagen and elastin, and layers of vascular smooth muscle cells. This gives the aortic wall the tensile strength to withstand the pressure of blood pumped from the heart during systole, and the elasticity to expand and accommodate the left ventricular stroke volume and to, subsequently, recoil to its original diameter and push the blood forward for systemic perfusion. Aortic aneurysm involves structural degradation of the aortic wall and focal dilatation of the aortic lumen. It is a devastating health problem with no effective treatment. Current management strategies for AAA patients include antihypertensive drugs and surgical repair for severe cases of AAA which are not without limitations and complications. A number of proteases (matrix metalloproteinases, serine and cystein proteases), and their inhibitors (tissue inhibitor of metalloproteases and cystatin) have been shown to contribute to AAA development and progression. In this review we will summarize the published literature on the role of ECM-regulatory proteins, mainly proteases and their inhibitors, in aortic function and aneurysm formation, with a focus on abdominal aortic aneurysm.