Gene expression profiles in the acutely dissected human aorta

Objectives: heritable connective tissue abnormalities and arterial hypertension may predispose to aortic dissection. This study evaluates gene expression profiles in the acutely dissected human aorta. Design, Materials and Methods: Atlas(TM) Human Broad Arrays I, II, and III (Clontech) were used to compare gene expression in acutely dissected (6 patients) and normal ascending aortas (6 multiorgan donors). The tissues were also compared macroscopically. Results: of 3537 genes analysed, 1250 (35%) were expressed in aortic tissue. For statistical analysis we focused on 627 genes, which had an intensity > 0.95 of the mean patients or controls. Dissected and adjacent macroscopically intact aorta displayed similar gene expression patterns. On the contrary, 66 genes were expressed significantly different in dissected aorta, compared with undiseased control aorta of multiorgan donors. Genes, predominantly upregulated in dissection, are involved in inflammation, in extracellular matrix proteolysis, in proliferation, translation and transcription. Predominantly downregulated genes code for extracellular matrix proteins, adhesion proteins and cytoskeleton proteins. Conclusion: our results demonstrate for the first time the complexity of the dissecting process on a molecular level. The ultimate dissection seems to be the dramatic endpoint of a long-lasting process of degradation and insufficient remodelling of the aortic wall. Altered patterns of gene expression suggest a pre-existing structural failure of the aortic wall, resulting in dissection.