BACKGROUND: Endothelin 1 has been implicated in various human diseases, including atherosclerosis. In this study, we examined the expression and localization of endothelin-converting enzyme-1 (ECE-1), the final key enzyme of endothelin 1 processing, in rat carotid arteries after balloon injury and in human coronary atherosclerotic lesions. METHODS AND RESULTS: ECE-1 mRNA levels and ECE activity in rat balloon-injured arteries started to increase between 2 and 5 days after injury. The endothelin 1 content of tissue in injured arteries was concomitantly increased. Immunohistochemical staining located ECE-1 signals in endothelial cells in uninjured arteries, whereas ECE-1 immunoreactivity was detected in neointimal smooth muscle cells in injured arteries 5 to 14 days after balloon denudation. The size of the neointima was effectively reduced by phosphoramidon, an inhibitor of neutral metalloproteases, including ECE-1. In human coronary atherosclerotic lesions, intense ECE-1 immunoreactivity was detected in subsets of cells embedded in atheromatous plaque that correspond to smooth muscle cells and macrophages, as identified by staining for smooth muscle alpha-actin and CD68 surface marker, respectively. CONCLUSIONS: The present study ascertained that ECE-1 is expressed in neointimal smooth muscle cells in rat balloon-injured arteries and in both smooth muscle cells and macrophages in human coronary atherosclerotic lesions. Blockade of ECE-1 was effective in reducing neointimal formation after balloon injury. Thus, ECE-1 may contribute to the process of injury-induced neointimal formation and atherosclerosis through the autocrine/paracrine effects of endothelin 1.
BACKGROUND:Endothelin 1 has been implicated in various human diseases, including atherosclerosis. In this study, we examined the expression and localization of endothelin-converting enzyme-1 (ECE-1), the final key enzyme of endothelin 1 processing, in rat carotid arteries after balloon injury and in humancoronary atherosclerotic lesions. METHODS AND RESULTS:ECE-1 mRNA levels and ECE activity in rat balloon-injured arteries started to increase between 2 and 5 days after injury. The endothelin 1 content of tissue in injured arteries was concomitantly increased. Immunohistochemical staining located ECE-1 signals in endothelial cells in uninjured arteries, whereas ECE-1 immunoreactivity was detected in neointimal smooth muscle cells in injured arteries 5 to 14 days after balloon denudation. The size of the neointima was effectively reduced by phosphoramidon, an inhibitor of neutral metalloproteases, including ECE-1. In humancoronary atherosclerotic lesions, intense ECE-1 immunoreactivity was detected in subsets of cells embedded in atheromatous plaque that correspond to smooth muscle cells and macrophages, as identified by staining for smooth muscle alpha-actin and CD68 surface marker, respectively. CONCLUSIONS: The present study ascertained that ECE-1 is expressed in neointimal smooth muscle cells in rat balloon-injured arteries and in both smooth muscle cells and macrophages in humancoronary atherosclerotic lesions. Blockade of ECE-1 was effective in reducing neointimal formation after balloon injury. Thus, ECE-1 may contribute to the process of injury-induced neointimal formation and atherosclerosis through the autocrine/paracrine effects of endothelin 1.
Authors: Peter Johnström; Tim D Fryer; Hugh K Richards; Janet J Maguire; John C Clark; John D Pickard; Anthony P Davenport Journal: Br J Pharmacol Date: 2010-02 Impact factor: 8.739