Dorsal-ventral difference in the aorta: Multiscale mechanical analysis and microarray analysis

Abstract

It gradually becomes clear that aortic walls are more compliant in the ventral side than the dorsal. This indicates that cyclic deformation of aortic wall is higher in the ventral side during heart beat, which may cause difference in the properties of smooth muscle cells (SMCs). In this study, we observed the dorsal-ventral (DV) difference in the contractility and RNA expression levels in rabbit thoracic aortas. Aortic walls were more contractile in the ventral side than the dorsal not only in tissue level but also in cellular level. Microarray analysis showed several genes with DV difference, including osteopontin with higher expression in the dorsal side and actin with higher expression in the ventral. Osteopontin stimulates DNA synthesis in SMCs and actin is one of the most important contractile proteins. Thus, SMCs in the dorsal side may have more synthetic phenotype and those in the ventral side more contractile.