Aortic valve stenosis (AS) is a chronic process related to a progressive mineralization of the aortic root and valve cusps. We found in human AS valves a high level of expression and enzymatic activity of ectonucleotide pyrophosphatase/phosphodiesterase-1 (ENPP-1), which correlated to the degree of mineralization. In vitro, inhibition of ENPP activity with ARL 67156 significantly reduced calcification of isolated valve interstitial cells. In a rat model of cardiovascular calcification, ARL 67156 significantly reduced calcification of the aortic root and valve cusps. This is the first study to demonstrate that increased expression and activity of ENPP-1 promotes the mineralization process in AS valves. Hence, inhibition of ectonucleotidase may represent a novel target of therapy for this frequent and serious cardiovascular disease.
