© Georg Thieme Verlag KG Stuttgart · New York
Accelerated smooth muscle cell apoptosis in occluded aorto-coronary saphenous vein grafts
25 April 2011 (online)
It has been suggested that apoptosis contributes to the pathogenesis of atherosclerosis and to the instable plaque syndrome. The role of apoptosis in aorto-coronary venous graft occlusion is unknown. Therefore, we compared the occurrence of smooth muscle cell (SMC) apoptosis and apoptosis-related molecular markers in occluded vein grafts (CABG) with native coronary artery disease. Neointimal SMC of occluded CABG (n = 30) and desobliterates from occluded native coronary arteries (n = 65) were immunohistochemically stained in situ for the detection of p53, bax, bcl-2 and TUNEL (TdT-mediated dUTP-biotin nick endlabeling). The occurrence of apoptosis-promoting molecular markers and concomitant SMC apoptosis (% positive stained SMC ± SE) was significantly increased in occluded CABG compared to coronary artery desobliterates (p53: 6.8 ± 2.3 versus 0 p < 0.005; bax: 5.4 ± 1.5 versus 3.6 ± 0.9 p < 0.05; TUNEL: 3.8 ± 1.7 versus 1.1 ± 0.4 p < 0.05). SMC apoptosis is significantly increased in occluded venous grafts compared to primary coronary artery disease, and may play a role in the pathogenesis of vein graft disease. The documented increase in apoptosis-promoting molecular markers could be the basis for new therapeutic strategies for the prevention of venous graft occlusion.