Immediate-early gene expression in human saphenous veins harvested during coronary artery bypass graft operations

Saphenous vein graft occlusion is a common late complication of coronary bypass grafting. Intimal smooth muscle cell hyperplasia is a component of this pathobiology, but the underlying molecular events are poorly understood. Immediate-early genes are activated shortly after growth stimulation and subserve cellular functions, which may contribute to intimal smooth muscle cell accumulation. In the present study, human saphenous vein grafts were harvested with minimal manipulation during coronary bypass and processed for isolation of total ribonucleic acid to examine changes in immediate-early gene expression of messenger ribonucleic acid by Northern blotting techniques. Thirty saphenous vein grafts were incubated at 4° C in Dulbecco's modified Eagle media from 30 minutes to 10 hours. The messenger ribonucleic acids for immediate-early genes c- fos and c- myc were weak or undetectable in controls but were increased (>10 times controls) within 1 hour (c- fos ) and persisted for at least 6 hours (c- myc ) after harvest. Our results demonstrate, for the first time in human vascular tissue, incipient immediate-early gene induction. This information may lead to molecular therapies to control saphenous vein graft disease.