Aortopathy in Bicuspid Aortic Valve and Marfan Syndrome is Characterized by a Lack of Activation Potential of the Epicardium in the Ascending Aorta

Patients with a bicuspid aortic valve (BAV) and Marfan syndrome (MFS) have increased susceptibility for development ofaortopathy. In the heart, epicardial cells expressing Wilms tumor suppressor protein (Wt1) are known to become activated after myocardial infarction. We hypothesize that epicardium covering the aorta might show a similar response in BAV and MFS in pathologic conditions.Non- and dilated ascending aorta specimen of BAV (n = 36), tricuspid aortic valve (TAV) (n = 23), and MFS (8) were investigated. The aorta was studied by immunohistochemistry and immunofluorescence, using Wt1 and endothelial nitric oxide, which regulates Wt1 expression. Functionality and therefore activity of Wt1 was confirmed by co-expression with retinaldehyde dehydrogenase-II enzyme in the same cells.