Distinct profiles of endothelial gene expression in hyperpermeable regions of the porcine aortic arch and thoracic aorta

Among the early events associated with atherosclerotic lesion development are increased macromolecular permeability of the endothelium and expression of genes that affect inflammation and oxidative state. The purpose of this study was to measure the expression of several atherosclerosis-related genes in endothelial cells scraped from arch and thoracic regions of the porcine aorta exhibiting elevated permeability. Aortae were collected from six swine that were exposed to circulating Evans blue dye (EBD), a marker of transendothelial albumin permeability. Endothelial cells were scraped from (1) white regions in the thoracic aorta, (2) light blue streaks and blue regions near ostia in the thoracic aorta, and (3) dark blue regions in the aortic arch. Expression levels of several genes were analyzed by real-time quantitative PCR. There were modest differences between the expression levels of several genes in cells from the light blue regions relative to those from white regions. In the dark blue regions, eNOS was drastically downregulated and MCP-1 was upregulated relative to their expression in both the white and light blue regions. The distinct levels of permeability and differences in gene expression profiles exhibited by cells from these different regions of the aorta may reflect corresponding differences in their hemodynamic environments.