Apoptosis and autophagy in human vein grafts replacing occluded coronary arteries in atherosclerosis

Abstract

Atherosclerosis is a chronic disease. For many decades vein grafts are used to replace occluded and suboccluded segments of coronary arteries. Restenosis is still a major problem today, as this chronic disease does not disappear when the occluded segments are replaced by autologous vein grafts. What are the cellular characteristics of this restenosis? Vein grafts obtained during surgical reinterventions were processed for light microscopy, SEM, TEM, immunohistochemistry (nuclear marker, smooth muscle cell marker, ..) and TUNEL (apoptosis).The cellular characteristics are accumulation of foam cells at the luminal side and smooth muscle cell death in the layer underneath. The remaining smooth muscle cells show nuclear fragmentation or apoptosis and remnants of cytoplasmic fragmentation or autophagy. Attempts are being made to develop drugs that might prevent the accumulation of foam cells and smooth muscle cell death in the aim to prevent the redevelopment of atherosclerotic plaques in the vein grafts.