Biomechanical factors in cardiovascular disease

Abstract

This Spotlight issue is focused on the influence of biomechanical forces induced by flowing blood on the development, function, and pathophysiology of the vasculature. The velocity and direction of blood flow vary at a temporal level with each heartbeat and changes spatially according to vascular anatomy. This concept appears to have been already appreciated in the early sixteenth century by the renaissance polymath Leonardo Da Vinci, who depicted swirling motions of blood following its interaction with the aortic valve,1 detailed drawings of which can be found in the Royal Library in Windsor Castle (http://www.royalcollection.org.uk/collection/919082/the-aortic-valve and http://www.royalcollection.org.uk/collection/919083/blood-flow-through-the-aortic-valve). The relationship between blood flow and the spatial location of atherosclerotic lesions was also noted by Virchow in 18562 and was brought into the modern era by Caro et al .,3 Nerem and Seed,4 Fry and colleagues,5 and Friedman et al .,6 who pioneered cross-disciplinary approaches by combining engineering with biology to assess vascular biomechanical responses. The vascular endothelium is a thin monolayer of cells that line the luminal side of all blood vessels. It serves as a barrier for the exchange of fluid, electrolytes, macromolecules, and cells between the intravascular space and surrounding tissue. It regulates leucocyte adhesion and trans-endothelial migration as well as platelet aggregation and smooth muscle function through the expression of adhesion and junctional molecules and by the biosynthesis of vasoactive substances, such as nitric oxide, prostacyclin, and endothelin-1. The endothelium is highly sensitive to haemodynamic shear stresses acting at the vessel luminal surface in the direction of blood flow. Although the mechanisms and structures by which endothelial cells sense wall shear stress are largely unknown, it is widely recognized that mechanical forces are an important determinant of endothelial cell function, gene expression, and structure. Ando and Yamamoto7 develop this concept by reviewing …